Support for writing multiple maxTargetSdk APIs to one file.

Since the rest of the support for per-SDK level enforcement is not in
place yet, we just write APIs with maxTargetSsk or P and Q to the same
file.

Test: atest class2greylisttest
Bug: 114361293
Change-Id: Ie6f3e8abf5480fc885230947ce2be19e326a309f
4 files changed