[SurfaceFlinger] Add hwc information to winscope:

* String blob of HWC dump
* Fill in HWC composition enum

Caveat is that only the primary display information is filled in.

Bug: 119443475
Test: Winscope trace
Change-Id: I246dc8df5e16388d8e58afeabfe944b158e1a39d
diff --git a/services/surfaceflinger/SurfaceTracing.cpp b/services/surfaceflinger/SurfaceTracing.cpp
index eb5c7de..c5556ec 100644
--- a/services/surfaceflinger/SurfaceTracing.cpp
+++ b/services/surfaceflinger/SurfaceTracing.cpp
@@ -170,6 +170,12 @@
     mFlinger.dumpOffscreenLayersProto(layers);
     entry.mutable_layers()->Swap(&layers);
 
+    if (mTraceFlags & SurfaceTracing::TRACE_HWC) {
+        std::string hwcDump;
+        mFlinger.dumpHwc(hwcDump);
+        entry.set_hwc_blob(hwcDump);
+    }
+
     return entry;
 }