Remove deapex support from java_*_import

prebuilt_apex/apex_set currently supports its deapexed contents to be
returned via a sibling java_import/java_sdk_import module. This is
necesssary for
1. dexpreopt/hiddenapi processing
2. usage as shared library

(1) is no longer necessary. this information is provided by the
top-level prebuilt apexes now

(2) is no longer possible since `exported_java_libs` has been removed in
https://r.android.com/3272110

This CL uses a hack for java_sdk_library_improt. Even though (1) is
provided by the top-level apex, there are still some places where
dexpreopt/hiddenapi processing visits the import modules. This CL uses
a bogus path to make analysis work. If this bogus path gets used, there
will be an error during ninja execution

Test: go test ./apex
Test: in internal lunch cf_x86_64_phone-next-userdebug (uses mainline
prebuilts)
Test: verified that file_list.txt is same
Bug: 368337090

Change-Id: I0ea2327f648f0fc60e337b232f7265e140772ffd