Add missing vendor_available: true property

Due to b/424439549, Soong wasn't enforcing that vendor modules could only link against
other vendor modules.  Add vendor_available to any modules that are being used by
vendor modules in order to allow re-enabling the error in Soong.

Bug: 424439549
Flag: EXEMPT build only fix
Test: builds
Change-Id: Ic1d5529ecdc2491d2cb50bae7a0e59a13743260c