Remove availability definitions for mbs APIs.

Definitions for these are provided in libandroid_support for API
levels that do not expose this in the stubs. For the rare cases where
libandroid_support is not being used this will result in a lower
quality diagnostic (undefined reference instead of "not available
until API 21"), but other fixes would also have that behavior because
the libandroid_support headers are *always* available, even if
libandroid_support won't be linked.

Test: Reverted xfailed tests for #1108 and reran tests with this
Bug: https://github.com/android/ndk/issues/1108
Change-Id: I371f5b9d7caeef8dc7c80f2f6d11280ecba119c9

0 files changed, 0 insertions, 0 deletions