Fix passed env var name in lit for Android tests.

The variable is actually called ANDROID_SERIAL.
This was not exercised on the bots until today.
Should fix the sanitizer-x86_64-linux failures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246898 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed