Don't hide NDK types behind API level guards.

The types are still needed if you want to target a lower API level
and use dlsym to conditionally access new APIs when running on new
devices.

Test: make checkbuild
Bug: https://github.com/android-ndk/ndk/issues/529
Change-Id: If5e41102b1badfd47f3625656058196373f119b3
9 files changed