Use envsetup.sh for the user-space and the kernel

 - refer to MORELLO_LLVM_PATH from the kernel build.config
 - move "source build/envsetup.sh" to emphasise it is now used
   both by the user-space and the kernel build stages

Change-Id: I7a622ce8b4fe5fd53472b81303c40739763d9ba6
3 jobs for !3 with patch-189777 in 46 minutes and 50 seconds (queued for 2 seconds)
latest detached
Status Job ID Name Coverage
  Build
passed #4164
build-firmware

00:20:01

 
  Build Android
failed #4165
build-android

00:26:49

 
  Test
skipped #4166
arm64
test-android
 
Name Stage Failure
failed
build-android Build Android
user	302m13.600s
sys 24m24.640s
Uploading artifacts for failed job
Uploading artifacts...
WARNING: build.env: no matching files
ERROR: No files to upload
Cleaning up file based variables
ERROR: Failed to cleanup volumes
ERROR: Job failed: exit code 1