Refactor: Migrate app build.gradle to Kotlin DSL (#2046)

.github/workflows/android.yml

@@ -32,11 +32,11 @@ jobs:
     - name: Validate Gradle wrapper
       uses: gradle/actions/wrapper-validation@v4
 
-    - name: Set up JDK 17
+    - name: Set up JDK 21
       uses: actions/setup-java@v4
       with:
-        java-version: '17'
-        distribution: 'zulu'
+        java-version: '21'
+        distribution: 'jetbrains'
 
     - name: Setup Gradle
       uses: gradle/actions/setup-gradle@v4
@@ -78,11 +78,11 @@ jobs:
         with:
           submodules: 'recursive'
 
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: '17'
-          distribution: 'zulu'
+          java-version: '21'
+          distribution: 'jetbrains'
 
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v4
@@ -118,8 +118,8 @@ jobs:
 
       - uses: actions/setup-java@v4
         with:
-          java-version: '17'
-          distribution: 'zulu'
+          java-version: '21'
+          distribution: 'jetbrains'
 
       - uses: gradle/actions/setup-gradle@v4
 

.github/workflows/release.yml

@@ -40,8 +40,8 @@ jobs:
     - name: Set up JDK 17
       uses: actions/setup-java@v4
       with:
-        java-version: '17'
-        distribution: 'zulu'
+        java-version: '21'
+        distribution: 'jetbrains'
         # Note: we don't use caches on release builds because we don't want to accidentally not have a virgin build machine
 
     - name: Build F-Droid release