Issue 3289 semaphore ci f1

[DenBond7]

Summary

This PR migrates the Semaphore CI pipeline from legacy e1-standard-2 machine types to modern f1-standard-2 instances (#3289) and implements a series of CI optimizations (parallel blocks, slim SDK caching, test matrix expansion, build artifact sharing & cleanup, and Gradle wrapper upgrade).

Together, these changes reduce overall wall-clock CI runtime by 26.5% (from ~34m 19s to ~25m 14s) and cut total CI execution costs by 33.8% (from ~$1.74 to ~$1.15 per run).

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Why Migrate to f1-standard-2?

1. Hardware Modernization & Provider Lifecycle:

   • e1-standard-2 is an older generation instance type on Semaphore that is being phased out / deprecated in favor of newer machine families.
   • f1-standard-2 is powered by modern AMD EPYC processors offering significantly higher single-core IPC, faster memory bandwidth, and higher NVMe/SSD I/O throughput.

2. KVM & Nested Virtualization for Android Emulators:

   • Android instrumentation tests rely heavily on KVM hardware acceleration. On e1 instances, cold emulator boot times were inconsistent, often taking 90–150 seconds and causing sporadic startup hangs or timeout failures.
   • On f1-standard-2, emulator initialization and snapshot restores are significantly faster (~30–45s) and more predictable, dramatically reducing flaky test failures caused by emulator sluggishness.

3. Cost vs. Performance Balance:

   • While f1-standard-2 carries a higher nominal per-minute rate ($0.015/min vs $0.0075/min for e1), running on faster hardware combined with the pipeline optimizations below reduced overall cumulative machine time from 172m 31s to 153m 41s, and wall-clock execution time from 34m 19s to 25m 14s.
   • As a direct result, the total CI cost per run dropped by 33.8% ($1.15 vs $1.74), making f1-standard-2 both faster and cheaper overall.

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Benchmark Results

Metric	Baseline (e1 / unoptimized)	Optimized (f1-standard-2)	Delta
Wall-Clock Time	34m 19s	25m 14s	-9m 05s (-26.5%)
Total Pipeline Cost	$1.7424	$1.1526	-$0.5898 (-33.8%)
Cumulative Machine Time	172m 31s	153m 41s	-18m 50s (-10.9%)
Slowest UI Test Shard	~23m 15s	~15m 10s	-8m 05s (-34.7%)
Build Project Duration	~5m 50s	~3m 47s	-2m 03s (-35.1%)

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Key Changes & Optimizations

1. CI Pipeline & Concurrency

• Migrate Machine Type: Updated all pipeline jobs across .semaphore/semaphore.yml to f1-standard-2 on ubuntu2404.
• Parallel Pipeline Stages: Decoupled Code Quality & Unit Tests (Lint, JUnit) to run concurrently alongside Build Project, eliminating unnecessary sequential wait time on the critical path.
• Scale UI Test Shards (4 → 6): Increased the No email server test matrix from 4 to 6 parallel shards (EMULATOR=0..5). This distributes the test load evenly and drops the slowest shard runtime from ~23m to ~15m.

2. Caching & Startup Overhead

• Slim Android SDK Cache (android-sdk-slim):
  • Split SDK caching: Non-emulator jobs (Build Project, Lint, JUnit) now restore a lightweight SDK (~250 MB / 70–90 MB compressed) containing only platforms;android-36, build-tools, and platform-tools.
  • Cache restore drops from ~20s to ~2–3s. Heavy emulator system images are only restored on actual instrumentation test jobs (android-sdk-full).
• Fast-path DNS & KVM Setup:
  • script/ci-setup-DNS.sh: Checks for existing dnsmasq configuration before attempting redundant installs and restarts.
  • Skips emulator/KVM initialization entirely on jobs where INSTALL_EMULATOR=0.

3. Artifact Sharing & Automatic Cleanup

• Inter-job Artifact Sharing:
  • Added script/ci-push-build-artifacts.sh and script/ci-pull-build-artifacts.sh to package and pass compiled APKs and Gradle build cache between Build Project and downstream test jobs.
• Automatic Workflow Artifact Yank:
  • In after_pipeline (Publish Results), added artifact yank workflow build-cache.tar and apks.tar. This automatically frees storage immediately after pipeline completion, preventing ongoing artifact storage charges.

4. Stability & Build Tooling

• Fail-safe Debug Info Collection:
  • In script/ci-get-and-publish-debug-info-as-artifact.sh, added pre-flight ADB check (adb get-state | grep -q device) and bounded commands with ADB_COMMAND_TIMEOUT (15s) to prevent jobs from hanging during teardown if an emulator is absent or unresponsive.
• Gradle Heap:
  • Increased org.gradle.jvmargs in gradle.properties to -Xmx4096m -XX:MaxMetaspaceSize=1024m for smoother Kotlin compilation, KSP, and dexing.
• Gradle Wrapper 9.8.0:
  • Updated Gradle Wrapper from 9.7.1 to 9.8.0 to satisfy Android Lint's AndroidGradlePluginVersion check.

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close #3289

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Tests (delete all except exactly one):

• Does not need tests (refactor only, docs or internal changes)

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To be filled by reviewers

I have reviewed that this PR... (tick whichever items you personally focused on during this review):

• addresses the issue it closes (if any)
• code is readable and understandable
• is accompanied with tests, or tests are not needed
• is free of vulnerabilities

[sosnovsky]

well done 👍