Roll back gradle build version for compatibility

Signed-off-by: Leo Ma <begeekmyfriend@gmail.com>

app/build.gradle

@@ -25,6 +25,6 @@ android {
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
     testCompile 'junit:junit:4.12'
-    compile 'com.android.support:appcompat-v7:25.3.0'
+    compile 'com.android.support:appcompat-v7:25.2.0'
     compile project(path: ':library')
 }

library/build.gradle

@@ -28,6 +28,6 @@ dependencies {
     androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
-    compile 'com.android.support:appcompat-v7:25.3.0'
+    compile 'com.android.support:appcompat-v7:25.2.0'
     testCompile 'junit:junit:4.12'
 }