Strip transition information from activityoptions once it is read.

The implementation of shared-element transitions takes the
ActivityOptions from the calling activity and sends them to
another activity. This means that any sensitive information
passed into ActivityManager via ActivityOptions can make its
way to an unrelated app. Recently a RemoteTransition object
was added which includes some sensitive information.

This CL strips the sensitive information from the activity
options after it is extracted so that it can't be sent
to the target.

Bug: 237290578
Test: atest ActivityManagerTest#testActivityManager_stripTransitionFromActivityOptions
Change-Id: Ic9f8062e67ab895292af75e97a9ce2f4aa45d467