Refactor HintSessionWrapper and move into CanvasContext

 * Move HintSessionWrapper into its own file
 * Refactor HintSessionWrapper initialization and lifecycle
 * Move HintSessionWrapper instance into CanvasContext
 * Have HintSessionWrapper do its own validity checks
 * Have HintSessionWrapper implicitly initialize when called

Bug: b/260267128
Bug: b/260224719
Test: manual
Change-Id: I69f89bb5ef601d1b5d9fca1a5da62256f2556da8
diff --git a/libs/hwui/Android.bp b/libs/hwui/Android.bp
index 88cfed9..fcc0126 100644
--- a/libs/hwui/Android.bp
+++ b/libs/hwui/Android.bp
@@ -570,6 +570,7 @@
                 "renderthread/VulkanSurface.cpp",
                 "renderthread/RenderProxy.cpp",
                 "renderthread/RenderThread.cpp",
+                "renderthread/HintSessionWrapper.cpp",
                 "service/GraphicsStatsService.cpp",
                 "thread/CommonPool.cpp",
                 "utils/GLUtils.cpp",