binderRpcTest: Use --whole-archive on Trusty

Fix test failures for BinderRpcTest on Trusty caused
by TEST_P code getting discarded by the linker because
the Trusty build system puts all object files in archives.
The fix is to use --whole-archive for binderRpcTest so
that all objects get linked.

Bug: 275620340
Test: binderRpcTest on Trusty
Change-Id: I9e3959c428ce6d8a39e0e0595a82ad5e8c3a43e2