Add cmdline as a compilation reason

Set the compiler reason to 'cmdline' when the compilation was
initiated from cmdline. This will effectivively eliminate the
'unknown' reason from our metrics (except in some corner cases)

(cherry picked from commit 303a702a)
Test: adb shell cmd compile ...
Bug: 188655918

Merged-In: I0cb6e9182530bc2d88975af185a0a8256fae2c2c
Change-Id: Id17ddceab2c9a4e5c30311e250817d8e0185cca6