Set target sdk level of AnnotationTest to 28

https://android-review.googlesource.com/c/platform/system/sepolicy/+/848615/
prevents apps targeting 29+ from executing files from its home
directory, which this test is doing.

Work around the restriction by explicitly setting API level to 28.

Bug: 116004356
Test: atest CtsSystemApiAnnotationTestCases
following error message does not shown
12-19 18:39:59.356 15885 15885 W ationTestRunner: type=1400 audit(0.0:89): avc: denied { execute } for path="/data/data/android.signature.cts.api.system_annotation/cache/agent8529617932972326708.so" dev="dm-6" ino=10347 scontext=u:r:untrusted_app:s0:c186,c257,c512,c768 tcontext=u:object_r:app_data_file:s0:c186,c257,c512,c768 tclass=file permissive=0 app=android.signature.cts.api.system_annotation
12-19 18:39:59.361 15885 15902 W stem_annotatio: Agent attach failed (result=1) : Unable to dlopen /data/user/0/android.signature.cts.api.system_annotation/cache/agent8529617932972326708.so: dlopen failed: couldn't map "/data/data/android.signature.cts.api.system_annotation/cache/agent8529617932972326708.so" segment 2: Permission denied

Change-Id: If1a79e52f18c8f520e73ef4216369d61ab788c0e
1 file changed