Prevent system app upgrading from multi-arch to single-arch

We should not let user to manully upgrade a system app which supports
multi-arch to a newer version which supports only one cpu abi. Take
webview as an example, if the user upgraded the webview to a version
supports only armeabi-v7a on Nexus 5X by mistake, then any app supports
only arm64-v8a and uses webview to display web contents would not work
properly then as loading a 32bit native lib inside a 64bit mode process
is not allowed.

Test: Manual

Change-Id: I567be7707fc18421ff686c1e8b1110dec517e06d
Signed-off-by: wangmingming1 <wangmingming1@xiaomi.com>

services/core/java/com/android/server/pm/PackageManagerService.java

@@ -17225,6 +17225,15 @@ public class PackageManagerService extends IPackageManager.Stub
                 return;
             }
 
+            // check if the new package supports all of the abis which the old package supports
+            boolean oldPkgSupportMultiArch = oldPackage.applicationInfo.secondaryCpuAbi != null;
+            boolean newPkgSupportMultiArch = pkg.applicationInfo.secondaryCpuAbi != null;
+            if (isSystemApp(oldPackage) && oldPkgSupportMultiArch && !newPkgSupportMultiArch) {
+                res.setError(INSTALL_FAILED_UPDATE_INCOMPATIBLE,
+                        "Update to package " + pkgName + " doesn't support multi arch");
+                return;
+            }
+
             // In case of rollback, remember per-user/profile install state
             allUsers = sUserManager.getUserIds();
             installedUsers = ps.queryInstalledUsers(allUsers, true);