Remove duplication of bootclasspath in LOCAL_JAVA_LIBRARIES

The bootclasspath libraries have direct dependencies now, so
remove them from LOCAL_JAVA_LIBRARIES so they don't also end
up in the classpath.

Test: m -j checkbuild
Test: m -j ANDROID_COMPILE_WITH_JACK=true java
Test: manually inspection of build-${TARGET_PRODUCT}.ninja
      only has expected changes
Test: no changes to system.img
Change-Id: Icbc8987468f237aa351708b33c3abe5ea3d1816e