AW: add isInstantApp to ApiHelperForO

This is necessary to remove downstream reflection which checks if the
embedder is an instant app. We add the API upstream to avoid introducing
another ApiHelperForO class downstream, since the base-layer one should
be fine.

R=paulmiller@chromium.org

Bug: 910019
Test: None
Change-Id: Ice29538bf15605e90bdff625fca4a85de2e4081e
Reviewed-on: https://chromium-review.googlesource.com/c/1353997Reviewed-by: Paul Miller <paulmiller@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612519}

base/android/java/src/org/chromium/base/compat/ApiHelperForO.java

@@ -5,6 +5,7 @@
 package org.chromium.base.compat;
 
 import android.annotation.TargetApi;
+import android.content.pm.PackageManager;
 import android.content.res.Configuration;
 import android.os.Build;
 import android.view.Display;
@@ -30,4 +31,9 @@ public final class ApiHelperForO {
     public static boolean isScreenWideColorGamut(Configuration configuration) {
         return configuration.isScreenWideColorGamut();
     }
+
+    /** See {@link PackageManager#isInstantApp() }. */
+    public static boolean isInstantApp(PackageManager packageManager) {
+        return packageManager.isInstantApp();
+    }
 }