remove target from every intermediate depFile

1. The current logic in the rsCppCmdLine only removes the target from the
first intermediated depFile, which is different from the logic in Make, see
https://source.corp.google.com/android/build/make/core/definitions.mk;l=1078
2. The expected logic, as that in Make, is to remove the target from every
intermediate depFile, if there are many, before the concatenation;
3. This bug would cause dependency cycle error, please check the bug number
below for more details;
4. The fix is to make sure the logic here is the same as that in Make.

Bug: 195036632
Test: m CtsRsCppTestCases with the converted Android.bp file (run more than
once to make sure no error occurs)
Test: manually checked the gen/rs/rs.stamp.d file to make sure there
is only one target on the top (the same as that built with the former
Android.mk file)
Test: TreeHugger

Change-Id: If79e3e5e7bc18a6fddcf56c0168daea93726afc6