use hidl-gen as the name of the code generator

-- Pass argv[0] as the name of the executable to run in auto-generated
   Android.mk files
-- Use hidl-gen in makefiles for the test executable

Change-Id: Ia35eaf9f66608d67730910c73436e4a7b8540752
Signed-off-by: Iliyan Malchev <malchev@google.com>
2 files changed