Remove configurationName from java library and hidden API

The configurationName was intended to separate the name of the module
from the name used in configuration (such as BootJars) so that the
child implementation library of a java_sdk_library on the bootclasspath
would have hidden API encoding performed on it just as for the main
java_library embedded within the java_sdk_library.

While that did use to work it no longer does as the test added in the
preceding change proves. It is not surprising that this regression does
not appear to have caused any issues as the the child implementation
library is only a build time artifact and not used at runtime.

In future the only modules that will require hidden API encoding are
those that are part of a bootclasspath module so there is no point in
maintaining this capability.

Bug: 179354495
Test: m droid
Change-Id: Ief8136fa9e98600cdd8d36108ec22edc2ebd7c69