Move java install rules into Soong

Remove the copy rules for LOCAL_SOONG_BUILT_INSTALLED, they will already
be created by Soong.

Also clean the soong host tools directory to remove any old copies of
java binaries.

Bug: 204136549
Test: m checkbuild
Change-Id: Ib6b5362ad59aa48770e48541430d6857846926c2