wifi(jar-jar): Jar-jar HIDL stubs to a separate namespace

This is statically linked by the wifi service, so should be jar-jar'ed
out to a separate namespace to avoid other components in system_server
calling our copy of the stubs.

Bug: 151475926
Test: Device boots up and connects to wifi networks.
Change-Id: I79247b72a3b5f6dabf38c3cb9705fb5ca0aa729f