Special Handling for Composable Methods in ProtectedPluginProcessor

This also adds handling for protecting objects contained within some
standard java collection types. Both of these changes were nessecary
to appropriately handle the new composable interfaces.

Bug: 432451019
Test: Manually checked processor output
Flag: NONE Transparent change to plugin protector
Change-Id: I124b8a4c91b2935513eab5f08b04e36ce113bd9b