Make ndk_prebuilt_* be available to any apex

The NDK prebuilts are implicitly used when building with sdk_version set.
Make the module types be available to any apex so that we don't need to
manually add apex_available property to the module definitions manually.

Exempt-From-Owner-Approval: cherry-pick from AOSP

Bug: 150999716
Test: m

Merged-In: I0870afa4c74b4a06ab1273dff84615778561ecc9
(cherry picked from commit e01e2282)
Change-Id: I0870afa4c74b4a06ab1273dff84615778561ecc9