Log if installers drop attribute installLocation

Installers that don't respect installLocation from APKs may result
in a bad user experience when users use adoptable storage. We still
allow this, but just log it.

Bug: 109668833
Test: Install APKs that explicitly set installLocation, and check
      the installLocation from install session.
Change-Id: Idfb33e79cb0df75af68faa3a70ea8559ea1ca003

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

@@ -2270,6 +2270,17 @@ public class PackageInstallerSession extends IPackageInstallerSession.Stub {
                         "Invalid filename: " + targetName);
             }
 
+            // Yell loudly if installers drop attribute installLocation when apps explicitly set.
+            if (apk.installLocation != PackageInfo.INSTALL_LOCATION_UNSPECIFIED) {
+                final String installerPackageName = getInstallerPackageName();
+                if (installerPackageName != null
+                        && (params.installLocation != apk.installLocation)) {
+                    Slog.wtf(TAG, installerPackageName
+                            + " drops manifest attribute android:installLocation in " + targetName
+                            + " for " + mPackageName);
+                }
+            }
+
             final File targetFile = new File(stageDir, targetName);
             resolveAndStageFileLocked(addedFile, targetFile);