Generate vintf without VNDK version

Current VINTF generation command expects BOARD_VNDK_VERSION and
PLATFORM_VNDK_VERSION, but these values are empty if VNDK is deprecated.
This change is to generate VINTF without VNDK version if those values
are empty.

Bug: 316829758
Test: AOSP CF build succeeded
Change-Id: I61fa0e0c80c7e367bd075ebe56bf85e7a1e3f782
1 file changed