Use caching and parallel for faster builds.

.github/workflows/android.yml

@@ -27,8 +27,8 @@ jobs:
         java-version: 17
         cache: gradle
 
-    - name: Validate Gradle Wrapper
-      uses: gradle/wrapper-validation-action@v3
+    - name: Setup Gradle and validate Gradle Wrapper
+      uses: gradle/actions/setup-gradle@v4
 
     - name: Build with Gradle
       run: ./gradlew qa

.github/workflows/diffuse.yml

@@ -31,8 +31,8 @@ jobs:
     - name: Install NDK
       run: echo "y" | ${ANDROID_SDK_ROOT}/cmdline-tools/latest/bin/sdkmanager --install "ndk;${{ env.NDK_VERSION }}"
 
-    - name: Validate Gradle Wrapper
-      uses: gradle/wrapper-validation-action@v1
+    - name: Setup Gradle and validate Gradle Wrapper
+      uses: gradle/actions/setup-gradle@v4
 
     - name: Cache base apk
       id: cache-base

gradle.properties

@@ -9,6 +9,9 @@ org.gradle.configuration-cache=false
 # See: https://docs.gradle.org/current/userguide/toolchains.html#sub:disable_auto_provision
 org.gradle.java.installations.auto-download=false
 
+org.gradle.caching=true
+org.gradle.parallel=true
+
 # Uncomment these to build libsignal from source.
 # libsignalClientPath=../libsignal
 # org.gradle.dependency.verification=lenient