envsetup.sh: Export LLVM_AOSP_PREBUILTS_VERSION with the current clang version from soong

Needed for KERNEL_CLANG_VERSION if TARGET_KERNEL_CLANG_VERSION hasn't been set by the device config

It's boring to change it on each Google change ...

Change-Id: I1d682611cbf6c60d7ae6227b0b5afde591adf471
Signed-off-by: Jackeagle <jackeagle102@gmail.com>
2 files changed