don't require 'O' for instant apps

It's unclear if we need this check; esp if we want to support
running legacy instant apps [i.e. instant apps that run pre-O
under the supervisor].

Test: Build and install instant app
Change-Id: I241f97e7960635af933e8fe1ddd86675789ec26c
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 9899cd4..911de0c 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -16431,13 +16431,13 @@
             Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
         }
 
-        // Ephemeral apps must have target SDK >= O.
-        // TODO: Update conditional and error message when O gets locked down
-        if (ephemeral && pkg.applicationInfo.targetSdkVersion <= Build.VERSION_CODES.N_MR1) {
-            res.setError(PackageManager.INSTALL_FAILED_EPHEMERAL_INVALID,
-                    "Ephemeral apps must have target SDK version of at least O");
-            return;
-        }
+//        // Ephemeral apps must have target SDK >= O.
+//        // TODO: Update conditional and error message when O gets locked down
+//        if (ephemeral && pkg.applicationInfo.targetSdkVersion <= Build.VERSION_CODES.N_MR1) {
+//            res.setError(PackageManager.INSTALL_FAILED_EPHEMERAL_INVALID,
+//                    "Ephemeral apps must have target SDK version of at least O");
+//            return;
+//        }
 
         if (pkg.applicationInfo.isStaticSharedLibrary()) {
             // Static shared libraries have synthetic package names