Enable generic JNI tests for MIPS32

We don't need to skip Generic JNI tests on MIPS32 since the original
issue has been fixed:
https://android-review.googlesource.com/#/q/topic:libjavacore_unload

Test: make test-art-target-gtest-jni_compiler_test on CI20

Change-Id: I98849ae2924ce886910c87f72813cb7a6465e8ad
1 file changed