Fix compilation issues with new kotlin compiler

These code failed with kotlinc v1.3.31.

1) Drawable.draw is marked as @NotNull. The declaration in both side
doesn't match.

2) Seems kotlin doesn't recognize getMatrix / setMatrix as a property
now. This is a little weird but may also because of @NotNull annotation
in setMatrix parameter.

Test: build with old and new compiler
Change-Id: Id7f34229e29bbceb6271a0648acf3512c10ed04c
Merged-In: Id5a85c787876248e610cc668f54e7bd40629d4e0