fix(location): Use LocationManager instead of FusedLocationProviderClient

[bgweaver]

Problem

On GrapheneOS (and other ROMs without Google Play Services), the Location
subsystem always shows Error(code=-1, message=No location available). This
is because FusedLocationProviderClient requires Play Services, which returns
null silently when unavailable.

All other subsystems (BLE, WiFi, Cellular, Satellite, GNSS) work correctly —
only the location stamping on detections was broken.

Fix

Replace FusedLocationProviderClient with Android's native LocationManager,
which works on any AOSP-based ROM without Play Services dependency.

Falls back through GPS → FUSED → NETWORK providers, and requests a single
update if no last known location is cached.

Tested on

• Google Pixel 8
• GrapheneOS (Android 16, API 36)
• No Sandboxed Play Services installed

Before: Location → Error(code=-1)
After: Location → Active, detections stamped with coordinates