build: Android APK builds working — debug (8.9MB) and release (2.0MB)

- Fix C++ std::std:: double namespace in oboe_bridge.cpp
- Auto-fetch Oboe headers from GitHub in build.rs
- Configure cargo cross-compilation (.cargo/config.toml) with NDK linkers
- Fix Gradle settings (dependencyResolutionManagement), signing configs,
  Compose LinearProgressIndicator API, and Android manifest theme
- Add Gradle wrapper, .gitignore for build artifacts
- arm64-v8a only (raptorq crate incompatible with armv7 32-bit)
- Release APK: 2.0MB signed with wzp-release key
- Debug APK: 8.9MB signed with wzp-debug key

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

android/app/src/main/AndroidManifest.xml

@@ -13,7 +13,7 @@
         android:name=".WzpApplication"
         android:label="WZ Phone"
         android:supportsRtl="true"
-        android:theme="@style/Theme.Material3.DayNight">
+        android:theme="@android:style/Theme.Material.Light.NoActionBar">
 
         <activity
             android:name=".ui.call.CallActivity"

android/app/src/main/java/com/wzp/ui/call/InCallScreen.kt

@@ -186,7 +186,7 @@ private fun AudioLevelBar(framesEncoded: Long) {
         )
         Spacer(modifier = Modifier.height(4.dp))
         LinearProgressIndicator(
-            progress = { level },
+            progress = level,
             modifier = Modifier
                 .fillMaxWidth(0.6f)
                 .height(6.dp)