runtests.sh: add help option

While the default behavior of runtests.sh is the
correct one (run _all_ the tests), there are some
other common use cases.

Add a "--help" option, which explains how to perform
other common tasks.

Bug: 35632708
Test: ./runtests.sh
Test: ./runtests.sh -r -e class com.android.server.wifi.WifiDiagnosticsTest#startLoggingRegistersLogEventHandler

Change-Id: I0f823bfbe271069b8af4aa9ec3bbd6074113ad3d
1 file changed
tree: c458f75aca52eb4395eea2e9e8f252393efde629
  1. libwifi_hal/
  2. libwifi_system/
  3. service/
  4. tests/
  5. PREUPLOAD.cfg