SF: Remove manual enum stringification

Upgrade to scoped enums where applicable. Pull GameMode from TimeStats
into libgui to plumb it as an enum rather than int32_t.

Bug: 185536303
Test: libsurfaceflinger_unittest
Change-Id: I81fdd24805757ef953484055ee867684eb94fecf
diff --git a/services/surfaceflinger/FrameTimeline/FrameTimeline.cpp b/services/surfaceflinger/FrameTimeline/FrameTimeline.cpp
index c294ff2..0c4e112 100644
--- a/services/surfaceflinger/FrameTimeline/FrameTimeline.cpp
+++ b/services/surfaceflinger/FrameTimeline/FrameTimeline.cpp
@@ -304,7 +304,7 @@
                            frametimeline::TimelineItem&& predictions,
                            std::shared_ptr<TimeStats> timeStats,
                            JankClassificationThresholds thresholds,
-                           TraceCookieCounter* traceCookieCounter, bool isBuffer, int32_t gameMode)
+                           TraceCookieCounter* traceCookieCounter, bool isBuffer, GameMode gameMode)
       : mToken(frameTimelineInfo.vsyncId),
         mInputEventId(frameTimelineInfo.inputEventId),
         mOwnerPid(ownerPid),
@@ -778,7 +778,7 @@
 
 std::shared_ptr<SurfaceFrame> FrameTimeline::createSurfaceFrameForToken(
         const FrameTimelineInfo& frameTimelineInfo, pid_t ownerPid, uid_t ownerUid, int32_t layerId,
-        std::string layerName, std::string debugName, bool isBuffer, int32_t gameMode) {
+        std::string layerName, std::string debugName, bool isBuffer, GameMode gameMode) {
     ATRACE_CALL();
     if (frameTimelineInfo.vsyncId == FrameTimelineInfo::INVALID_VSYNC_ID) {
         return std::make_shared<SurfaceFrame>(frameTimelineInfo, ownerPid, ownerUid, layerId,