Query for OpenXr Runtime status on Android startup

Attempts to create an XrInstance before creating an `OpenXrDevice` on
Android. This ensures that the OpenXr runtime can actually be supported
on the current device before we create the device that would attempt to
supply an OpenXr Session. This early creation of the XrInstance also
allows us to query for the supported environment blend modes at device
creation and allows us to accurately report if the device can support
a non-opaque blend mode, at which point it will take priority over
ARCore for "immersive-ar" sessions as well.

Note that initial plumbing of the service/webcontents was based on:
https://crrev.com/c/4632076

Bug: 1435548,1458584
Change-Id: Ibb8e04014c67da03cd9bab92f011901d2d88d607
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5146928
Reviewed-by: Brandon Jones <bajones@chromium.org>
Commit-Queue: Alexander Cooper <alcooper@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1242227}

diff --git a/device/vr/orientation/orientation_device_provider.h b/device/vr/orientation/orientation_device_provider.h
index 4076e97..2542fc6 100644
--- a/device/vr/orientation/orientation_device_provider.h
+++ b/device/vr/orientation/orientation_device_provider.h

@@ -30,7 +30,8 @@
 
   ~VROrientationDeviceProvider() override;
 
-  void Initialize(VRDeviceProviderClient* client) override;
+  void Initialize(VRDeviceProviderClient* client,
+                  content::WebContents* initializing_web_contents) override;
 
   bool Initialized() override;