Drop prebuilt files to android source tree.

CtsShim.apk
package: name=com.android.cts.ctsshim
versionCode=31
versionName=12-7464984
platformBuildVersionName=S
compileSdkVersion=31
compileSdkVersionCodename=S
sdkVersion:24
targetSdkVersion:28

CtsShimPriv.apk
package: name=com.android.cts.priv.ctsshim
versionCode=31
versionName=12-7464984
platformBuildVersionName=S
compileSdkVersion=31
compileSdkVersionCodename=S
sdkVersion:24
targetSdkVersion:28

CtsShim.apk
package: name=com.android.cts.ctsshim
versionCode=31
versionName=12-7464984
platformBuildVersionName=S
compileSdkVersion=31
compileSdkVersionCodename=S
sdkVersion:24
targetSdkVersion:28

CtsShimPriv.apk
package: name=com.android.cts.priv.ctsshim
versionCode=31
versionName=12-7464984
platformBuildVersionName=S
compileSdkVersion=31
compileSdkVersionCodename=S
sdkVersion:24
targetSdkVersion:28

Built here: ab/7464984

This build IS suitable for public release.

The change is generated with prebuilt drop tool.

Test: presubmit
Bug: 188062003
Bug: 191262663
Change-Id: I92132d00e248c6d4cc2488af346ddc032e8c727a