Add minimal Oboe audio library example

Based on the demo in the oboe-rs repo this is a minimal example that
runs with GameActivity and plays a 440Hz sine wave

Author: rib

Cargo.toml

@@ -7,6 +7,7 @@ exclude = [
     "examples/agdk-mainloop",
     "examples/agdk-winit-wgpu",
     "examples/agdk-egui",
+    "examples/agdk-oboe",
     "examples/na-mainloop",
     "examples/na-winit-wgpu",
     "examples/na-subclass-jni"

examples/agdk-oboe/.gitignore

@@ -0,0 +1,21 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
+local.properties
+*.so
+
+# Added by cargo
+
+/target
+Cargo.lock

examples/agdk-oboe/.idea/.gitignore

@@ -0,0 +1,17 @@
+[package]
+name = "agdk-oboe"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+log = "0.4"
+android_logger = "0.11.0"
+android-activity = { path="../../android-activity", features = ["game-activity"] }
+oboe = { version = "0.4", features = ["java-interface"] }
+atomic_float = "0.1"
+
+[lib]
+name="main"
+crate_type=["cdylib"]

examples/agdk-oboe/.idea/compiler.xml

@@ -0,0 +1,16 @@
+This is a minimal test application based on `GameActivity` that just
+runs a mainloop based on android_activity::poll_events() and plays a
+sine wave audio test using the Oboe audio library.
+
+```
+export ANDROID_NDK_HOME="path/to/ndk"
+export ANDROID_HOME="path/to/sdk"
+
+rustup target add aarch64-linux-android
+cargo install cargo-ndk
+
+cargo ndk -t arm64-v8a -o app/src/main/jniLibs/  build
+./gradlew build
+./gradlew installDebug
+adb shell am start -n co.realfit.agdkoboe/.MainActivity
+```

examples/agdk-oboe/.idea/gradle.xml

@@ -0,0 +1 @@
+/build