Drop prebuilt files to android source tree.

CtsShim.apk
package: name=com.android.cts.ctsshim
versionCode=31
versionName=12-7533747
platformBuildVersionName=12
compileSdkVersion=31
compileSdkVersionCodename=12
sdkVersion:24
targetSdkVersion:28

CtsShimPriv.apk
package: name=com.android.cts.priv.ctsshim
versionCode=31
versionName=12-7533747
platformBuildVersionName=12
compileSdkVersion=31
compileSdkVersionCodename=12
sdkVersion:24
targetSdkVersion:28

CtsShim.apk
package: name=com.android.cts.ctsshim
versionCode=31
versionName=12-7533747
platformBuildVersionName=12
compileSdkVersion=31
compileSdkVersionCodename=12
sdkVersion:24
targetSdkVersion:28

CtsShimPriv.apk
package: name=com.android.cts.priv.ctsshim
versionCode=31
versionName=12-7533747
platformBuildVersionName=12
compileSdkVersion=31
compileSdkVersionCodename=12
sdkVersion:24
targetSdkVersion:28

Built here: ab/7533747

This build IS suitable for public release.

The change is generated with prebuilt drop tool.

Test: presubmit
Bug: 188062003
Change-Id: Ib94d2f69593e34bbe7115f974bd5385003d1af4c