Add maxTargetSdk restriction to unused APIs.

These are APIs that have @UnsupportedAppUsage but for which we don't
have any evidence of them currently being used, so should be safe to
remove from the unsupported list.

This is a resubmit of ag/12929664 with some APIs excluded that caused
test failures; see bugs 171886397, 171888296, 171864568.

APIs excluded:
Landroid/bluetooth/le/ScanRecord;->parseFromBytes([B)Landroid/bluetooth/le/ScanRecord;
Landroid/os/Process;->myPpid()I
Landroid/os/SharedMemory;->getFd()I
Landroid/hardware/input/InputManager;->INJECT_INPUT_EVENT_MODE_WAIT_FOR_FINISH:I

Bug: 170729553
Test: Treehugger
Change-Id: I8285daa8530260251ecad6f3f38f98e263629ca7