MediaShareActivity: Add documentation explaining use of checkFacebookAccountStatus method in Activity.onStart
MediaShareActivity.onCreate: Remove call to checkFacebookAccountStatus - unneeded right now, but may be needed later to prevent unnecessary work
FacebookAccount: Add new method isSessionUsable
FacebookAccount: Add javadoc for class
MediaShareActivity.checkFacebookAccountStatus: Use FacebookAccount.isSessionUsable method for checking Facebook account status
MediaShareActivity.uploadImage: Remove parameter 'Uri mediaUri' and add parameter 'File imageFile'. Also update code that uses this method.
MediaShareActivity: Make method uploadImage static in preparation for moving it to FacebookAccount
Move MediaShareActivity.uploadImage to FacebookAccount and update references accordingly
MediaShareActivity.checkFacebookAccountStatus: Remove variable fbSession - no longer used
FacebookAccount: Make method getSession private
FacebookAccount.uploadImage: Use session variable directly instead of calling getSession
FacebookAccount.uploadImage: Remove TODO about moving class
FacebookAccount: Remove method getSession - unused
FacebookAccount.uploadImage: Add javadoc
MediaShareActivity.onStart: Improve documentation comment for call to checkFacebookAccountStatus
MediaShareActivity: Add TODO about validating input Uri
MediaShareActivity.checkFacebookAccountStatus: Correct mistake made earlier - reverse if condition
MediaShareActivity.checkFacebookAccountStatus: Remove unnecessary local variable creation
MediaShareActivity.checkFacebookAccountStatus: Instead of creating a new instance of NoActiveSessionDialogFragment every time, create one instance and use it each time, since we don't care about maintaining state for the dialog