Add modules for converting java modules between host and device

java_device_for_host and java_host_for_device allow treating a
device module as a host module and vice versa.  They will be useful
for converting layoutlib and robolectric to Soong, as these modules
run device java code on the host.

Bug: 117920228
Test: device_host_converter_test.go
Change-Id: Ia9a371fb41a97bc16338097f3ce8b40099744167