docs(android): avoid duplicate location permission

[huytdps13400]

Bug description

Closes #1338.

The manual Android setup used <uses-permission> for ACCESS_FINE_LOCATION, while the RxAndroidBle dependency declares the same permission with <uses-permission-sdk-23>. Adding android:maxSdkVersion="30" to the README snippet therefore left two differently scoped declarations in the merged manifest, which Google Play rejects.

Details

• Use <uses-permission-sdk-23> in both manual Android permission examples so the app manifest merges with the RxAndroidBle declaration.
• Clarify why the tag must match and when runtime location permission is no longer requested.
• Keep runtime and config-plugin behavior unchanged.

This follows the Android manifest merger priority rules and the official <uses-permission-sdk-23> documentation.

Verification

• npx --yes prettier@3.0.3 --check README.md
• git diff --check
• Minimal AGP 8.8.0 app using RxAndroidBle 1.17.2:
  • Before: merged manifest contained two ACCESS_FINE_LOCATION declarations (uses-permission with max SDK 30 plus uses-permission-sdk-23 without it).
  • After: :app:processDebugMainManifest succeeds and the merged manifest contains exactly one uses-permission-sdk-23 declaration with android:maxSdkVersion="30".