pdk: add bouncycastle-host javalib.jar to platform.zip

Add javalib.jar from bouncycastle-host to the platform.zip to allow
building dumpkey.jar, which is necessary to build recovery.
Host java libraries have no classes.jar, so they have to be kept
in a separate list fromt target java libraries.  Also add an implicit
rule to copy the host files out of the pdk fusion intermediates.

Bug: 12186985
Change-Id: I03ddf9810bc7a4ef7aac8427c4607d9eea27cc6b