Avoid printing exception for valid code execution path

[tobrun]

This PR avoids printing the exception message as:

 java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.os.BaseBundle.getBoolean(java.lang.String, boolean)' on a null object reference
        at com.mapbox.mapboxsdk.storage.FileSource.getCachePath(FileSource.java:88)
        at com.mapbox.mapboxsdk.storage.FileSource$FileDirsPathsTask.doInBackground(FileSource.java:165)
        at com.mapbox.mapboxsdk.storage.FileSource$FileDirsPathsTask.doInBackground(FileSource.java:155)
        at android.os.AsyncTask$2.call(AsyncTask.java:304)
        at java.util.concurrent.FutureTask.run(FutureTask.java:237)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
        at java.lang.Thread.run(Thread.java:761)

This occurs when the hosting app doesn't have any metadata setup in their AndroidManifest.xml. This is a valid use-case, this PR avoids throwing the exception, and the code change doesn't impact the business logic involved.

[tobrun]

This PR refs #13096 (comment)