Recovery: remove wiping of res folder

The rm -rf of the res folder wipes out all of the TWRP theme and
images. Remove this so that TWRP will work properly.

Change-Id: I27c372d53eaae3cc8b476a909c2d3f3fc4fcb558
build: set qcom media variant to root path

Change-Id: If7d0dc3fc1789b14f5272be46c13a9146575ce79