Fix issues in Android test projects setup.

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/android-butterknife/app/build.gradle

@@ -21,6 +21,11 @@ android {
         }
     }
 
+    compileOptions {
+        sourceCompatibility 1.8
+        targetCompatibility 1.8
+    }
+
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
     }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/android-databinding/app/build.gradle

@@ -19,6 +19,12 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+
+    compileOptions {
+        sourceCompatibility 1.8
+        targetCompatibility 1.8
+    }
+
     dataBinding {
         enabled = true
     }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/android-databinding/library/build.gradle

@@ -21,6 +21,11 @@ android {
         }
     }
 
+    compileOptions {
+        sourceCompatibility 1.8
+        targetCompatibility 1.8
+    }
+
     dataBinding { enabled = true }
 }
 

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/android-dbflow/app/build.gradle

@@ -16,6 +16,11 @@ android {
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
     }
+
+    compileOptions {
+        sourceCompatibility 1.8
+        targetCompatibility 1.8
+    }
 }
 
 def dbflow_version = "3.1.1"

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/android-realm/build.gradle

@@ -43,6 +43,11 @@ android {
         incremental false
     }
 
+    compileOptions {
+        sourceCompatibility 1.8
+        targetCompatibility 1.8
+    }
+
     packagingOptions {
         // Workaround for org.jetbrains.kotlin.gradle.Kapt3Android33IT#testRealm
         // Android Plugin 3.3.2 fails with:

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/androidx-navigation-safe-args/build.gradle

@@ -34,6 +34,11 @@ android {
         }
     }
 
+    compileOptions {
+        sourceCompatibility 1.8
+        targetCompatibility 1.8
+    }
+
     dexOptions {
         incremental false
     }