Ci: Add Gradle caching and cleanup properties

This commit introduces Gradle caching to the Android GitHub Actions workflow. The `actions/cache@v4` action is added to multiple jobs to cache `~/.gradle/caches` and `~/.gradle/wrapper`, keyed by the operating system and hash of Gradle files.

Additionally, the cleanup step has been updated to remove `local.properties` instead of `secret.properties`.

Author: eby-dev

.github/workflows/android.yml

@@ -88,6 +88,13 @@ jobs:
           path: vendor/bundle
           key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
 
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+
       - name: Install Ruby Dependencies
         run: |
           bundle config set path 'vendor/bundle'
@@ -126,7 +133,7 @@ jobs:
         run: |
           rm -f ${{ env.KEYSTORE_FILE }}
           rm -f app/${{ env.GOOGLE_PLAY_JSON }}
-          rm -f secret.properties
+          rm -f local.properties
 
   unit-test:
     name: Unit Tests
@@ -148,6 +155,13 @@ jobs:
           path: vendor/bundle
           key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
 
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+
       - run: |
           bundle config set path 'vendor/bundle'
           bundle install
@@ -202,6 +216,13 @@ jobs:
           path: vendor/bundle
           key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
 
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+
       - run: |
           bundle config set path 'vendor/bundle'
           bundle install
@@ -236,6 +257,13 @@ jobs:
           path: vendor/bundle
           key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
 
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+
       - run: |
           bundle config set path 'vendor/bundle'
           bundle install
@@ -267,6 +295,13 @@ jobs:
           path: vendor/bundle
           key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
 
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+
       - run: |
           bundle config set path 'vendor/bundle'
           bundle install