title: How to fix Android compatibility warnings
body: <p>I have an app that is targeting Android 9 and I noticed in the Google Play prelaunch report a new section called Android compatibility. This new section lists warnings or errors related to the usage of unsupported APIs. The following is one of the problems and is listed as a greylisted API. Can someone explain which is the unsupported API in this case? The usage seems to be coming from the Android support library and not my code.</p>
  
  <pre><code>StrictMode policy violation: android.os.strictmode.NonSdkApiUsedViolation: Landroid/view/ViewGroup;-&gt;makeOptionalFitsSystemWindows()V
      at android.os.StrictMode.lambda$static$1(StrictMode.java:428)
      at android.os.-$$Lambda$StrictMode$lu9ekkHJ2HMz0jd3F8K8MnhenxQ.accept(Unknown Source:2)
      at java.lang.Class.getDeclaredMethodInternal(Native Method)
      at java.lang.Class.getPublicMethodRecursive(Class.java:2075)
      at java.lang.Class.getMethod(Class.java:2063)
      at java.lang.Class.getMethod(Class.java:1690)
      at android.support.v7.widget.ViewUtils.makeOptionalFitsSystemWindows(ViewUtils.java:84)
      at android.support.v7.app.AppCompatDelegateImpl.createSubDecor(AppCompatDelegateImpl.java:685)
      at android.support.v7.app.AppCompatDelegateImpl.ensureSubDecor(AppCompatDelegateImpl.java:518)
      at android.support.v7.app.AppCompatDelegateImpl.onPostCreate(AppCompatDelegateImpl.java:299)
      at android.support.v7.app.AppCompatActivity.onPostCreate(AppCompatActivity.java:98)
      at android.app.Instrumentation.callActivityOnPostCreate(Instrumentation.java:1342)
      at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3002)
      at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:180)
      at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:165)
      at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:142)
      at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70)
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1816)
      at android.os.Handler.dispatchMessage(Handler.java:106)
      at android.os.Looper.loop(Looper.java:193)
      at android.app.ActivityThread.main(ActivityThread.java:6718)
      at java.lang.reflect.Method.invoke(Native Method)
      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
  </code></pre>