Initial commit: Pezkuwi Wallet Android

Security hardened release:
- Code obfuscation enabled (minifyEnabled=true, shrinkResources=true)
- Sensitive files excluded (google-services.json, keystores)
- Branch.io key moved to BuildConfig placeholder
- Updated dependencies: OkHttp 4.12.0, Gson 2.10.1, BouncyCastle 1.77
- Comprehensive ProGuard rules for crypto wallet
- Navigation 2.7.7, Lifecycle 2.7.0, ConstraintLayout 2.1.4

.github/workflows/install/action.yml

@@ -0,0 +1,37 @@
+name: Install dependencies for Android build
+description: Contains all dependencies for Android build
+runs:
+  using: "composite"
+  steps:
+    - name: ☕️ Install Java
+      uses: actions/setup-java@v4.0.0
+      with:
+        distribution: 'temurin'
+        java-version: '17'
+        cache: 'gradle'
+
+    - name: Setup Android SDK
+      uses: android-actions/setup-android@v3
+      with:
+        cmdline-tools-version: 12266719
+
+    - name: Install NDK
+      run: echo "y" | sudo ${ANDROID_SDK_ROOT}/cmdline-tools/16.0/bin/sdkmanager --install "ndk;26.1.10909125" --sdk_root=${ANDROID_SDK_ROOT}
+      shell: bash
+
+    - name: Set ndk.dir in local.properties
+      run: echo "ndk.dir=${{ steps.setup-ndk.outputs.ndk-path }}" >> local.properties
+      shell: bash
+
+    - name: 🦀 Install Rust
+      uses: dtolnay/rust-toolchain@stable
+      with:
+        components: rustfmt, clippy
+
+    - name: Add targets
+      run: |
+        rustup target add armv7-linux-androideabi
+        rustup target add i686-linux-android
+        rustup target add x86_64-linux-android
+        rustup target add aarch64-linux-android
+      shell: bash