drm: Remove libbinder as a static library.

Letting the library be statically linked does a couple of bad things:
- (importantly) allows its internal implementation details to become frozen
- (still important) uses extra space on this device

For these reasons, it is being made shared-only.

Test: boot Pixel 2
Bug: 111454508

Test:
atest android.drm.cts.DRMTest
...
=============== Summary ===============
Total Run time: 36s
1/1 modules completed
Total Tests       : 11
PASSED            : 11
FAILED            : 0
============== End of Results ==============

Change-Id: I3b6b208a6cc7dcfdd8255db38509e616a7e375d0