Fix Android hello-world gain and validate audio levels

[linuxificator]

Corrects the Android hello-world master gain from V2.0 to V10.0 after verifying AMY's V control is a 0..10 bus/master scale whose final mixer applies a 0.1 factor. Adds test-triggered four-second signed-16-bit WAV capture at two points: the raw AMY render stream and the exact callback buffer handed to Oboe. CI checks 48 kHz stereo format, byte-for-byte AMY-to-Oboe identity, a minimum -6 dBFS peak, and absence of full-scale clipping, and retains both WAVs plus level statistics as an artifact.

Validation at V2.0 measured peak -16.710 dBFS / RMS -21.308 dBFS with zero AMY-to-Oboe differences. Validation at V10.0 measured peak -2.721 dBFS / RMS about -7.2 dBFS, zero clipping, and zero AMY-to-Oboe differences. This demonstrates that the reported low volume originated in the hello-world AMY gain setting, not attenuation in the Oboe adapter.

Final validation: Android AMY run 32630088165 passed the socket regression, AAR/APK build, two cold emulator launches, audio-level analysis, and audio capture artifact upload.