Rather than have a special white list to contain the names of modules
that provide additional hiddenapi for modules on the bootclasspath
this defines a convention that such modules must have a name which is
of the format <x>-hiddenapi, where <x> is the name of the module on the
bootclasspath.
Bug: 73711752
Test: make droid && flashall -w && atest -p cts/tests/signature
Change-Id: Ib2d69dea9541b60a9bb81496f00edb65036d1ebb