Disable PluginVmFullscreen and ExoLockNotification for M91

This feature is pushed from M91 to M92.

Disabling on HEAD, then merge to M91, then revert this CL to have
enabled by default for M92.

(cherry picked from commit 0a9a6fc)

Bug: 1144780
Change-Id: Ic5d1c1181d8c65f602e6c67a1a0ae5e299b2a06d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2823324
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Commit-Queue: Timothy Loh <timloh@chromium.org>
Auto-Submit: Joel Hockey <joelhockey@chromium.org>
Reviewed-by: Timothy Loh <timloh@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#872303}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2825076
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/4472@{#54}
Cr-Branched-From: 3d60439-refs/heads/master@{#870763}

ash/constants/ash_features.cc

@@ -313,7 +313,7 @@ const base::Feature kExoPointerLock{"ExoPointerLock",
 
 // Enable or disable bubble showing when an application gains any UI lock.
 const base::Feature kExoLockNotification{"ExoLockNotification",
-                                         base::FEATURE_ENABLED_BY_DEFAULT};
+                                         base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Enables policy that controls feature to allow Family Link accounts on school
 // owned devices.
@@ -520,7 +520,7 @@ const base::Feature kPinSetupForFamilyLink{"PinSetupForFamilyLink",
 
 // Hides shelf in immersive mode and allows esc hold to exit.
 const base::Feature kPluginVmFullscreen{"PluginVmFullscreen",
-                                        base::FEATURE_ENABLED_BY_DEFAULT};
+                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Controls whether the camera permissions should be shown in the Plugin
 // VM app settings.