Fix kotlin nullable errors in TrustTests am: 5f70c1728f

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2744073

Change-Id: I56ea6a1ed4b337bccf5c78d93455684419c94b32
Signed-off-by: Automerger Merge Worker <[email protected]>