Add RollbackImpactLevel options to PackageManagerShellCommand.

```
42813537:
  -state: available
  -stateDescription:
  -timestamp: 2024-03-26T22:31:09.417925Z
  -rollbackLifetimeMillis: 0
  -rollbackUserImpact: 1
  -isStaged: false
  -originalSessionId: 1081878435
  -packages:
    com.google.android.gmscore.companion 26010 -> 26010 [2]
  -extensionVersions:
    {30=12, 31=12, 33=12, 34=12, 1000000=12}
```

Bug: 291137901
Change-Id: Ia5e0e3a2aba1ab179e05ac064603b3d38bf7d07d
Test: lunch aosp_cf_x86_64_only_phone-trunk_staging-eng && m && acloud create --local-image && adb install --enable-rollback 2 --rollback-impact-level 1 companion.apk