repocache: Display usage with '--help'
repocache: Display usage with '--help'

Change-Id: I1e0c40967ee67e105e64222fcefbe866c8e96719
Signed-off-by: Adrian DC <01fb3892f39957945220431e7409156544d2f041@gmail.com>

AdrianDC/android_development_shell_tools,AdrianDC/android_development_shell_tools