vending: suppress EMUI InstallDistActivity; implement splitDeferred

- Add USER_ACTION_NOT_REQUIRED to SessionParams in installPackagesInternal()
  for API 31+ (Android 12+) to prevent Huawei EMUI InstallDistActivity from
  intercepting every PackageInstaller session commit with a confirmation dialog.

- Implement splitDeferred() in SplitInstallService to route deferred DFM
  install requests through splitInstallFlow() instead of being a no-op stub.
  Previously, apps like Facebook would fall back to startInstall() for each
  deferred module, triggering additional PackageInstaller sessions and
  additional InstallDistActivity dialogs on EMUI.

Fixes: microg#3541

Author: grenadin

vending-app/src/main/kotlin/com/android/vending/installer/Install.kt

@@ -13,6 +13,7 @@ import android.content.pm.PackageInfo
 import android.content.pm.PackageInstaller
 import android.content.pm.PackageInstaller.SessionParams
 import android.content.pm.PackageManager
+import android.os.Build.VERSION.SDK_INT
 import android.util.Log
 import androidx.annotation.RequiresApi
 import androidx.core.app.PendingIntentCompat
@@ -118,6 +119,12 @@ private suspend fun Context.installPackagesInternal(
     val key = computeUniqueKey(packageName, componentNames)
     params.setAppLabel(key)
     params.setInstallLocation(PackageInfo.INSTALL_LOCATION_INTERNAL_ONLY)
+    // Suppress EMUI (Huawei) InstallDistActivity confirmation dialog for every session.
+    // Without this flag, EMUI intercepts each PackageInstaller session and shows a
+    // mandatory user-confirmation dialog — including for Dynamic Feature Module installs.
+    if (SDK_INT >= 31) {
+        params.setRequireUserAction(SessionParams.USER_ACTION_NOT_REQUIRED)
+    }
     try {
         @SuppressLint("PrivateApi") val method = SessionParams::class.java.getDeclaredMethod(
                 "setDontKillApp", Boolean::class.javaPrimitiveType

vending-app/src/main/kotlin/com/google/android/finsky/splitinstallservice/SplitInstallService.kt

@@ -91,8 +91,27 @@ class SplitInstallServiceImpl(private val installManager: SplitInstallManager, p
 
     override fun splitDeferred(targetPackage: String, splits: List<Bundle>, bundle0: Bundle, callback: ISplitInstallServiceCallback) {
         val packageName = PackageUtils.getAndCheckCallingPackage(context, targetPackage)!!
-        Log.w(TAG, "splitDeferred(${splits.joinToString()}) called for $packageName, but is not implemented")
-        runCatching { callback.onDeferredInstall(Bundle()) }
+        Log.d(TAG, "splitDeferred(${splits.joinToString()}) called for $packageName")
+        // Deferred installs are background pre-fetch requests (e.g. Facebook DFMs like pytorch/papaya).
+        // If we only ACK without actually installing, the app falls back to calling startInstall()
+        // for the same modules later — which triggers another PackageInstaller session and, on EMUI,
+        // another InstallDistActivity confirmation dialog per module.
+        // Fix: route deferred requests through the same install flow as startInstall().
+        if (VendingPreferences.isSplitInstallEnabled(context)) {
+            lifecycleScope.launch {
+                runCatching {
+                    installManager.splitInstallFlow(packageName, splits)
+                    Log.d(TAG, "splitDeferred install complete for $packageName")
+                }.onFailure { e ->
+                    Log.w(TAG, "splitDeferred install failed for $packageName: ${e.message}")
+                }
+                // Always ACK so the app is not left waiting.
+                runCatching { callback.onDeferredInstall(Bundle()) }
+            }
+        } else {
+            Log.w(TAG, "splitDeferred rejected for $packageName, service is disabled")
+            runCatching { callback.onDeferredInstall(Bundle()) }
+        }
     }
 
     override fun getSessionState2(targetPackage: String, sessionId: Int, callback: ISplitInstallServiceCallback) {