mark fuzz test flaky since it may fail on some platforms

NOTRY=true
TBR=bungeman@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2277893004

Review-Url: https://codereview.chromium.org/2277893004
diff --git a/tests/PathOpsOpTest.cpp b/tests/PathOpsOpTest.cpp
index d659e88..c5e8c38 100644
--- a/tests/PathOpsOpTest.cpp
+++ b/tests/PathOpsOpTest.cpp
@@ -6976,7 +6976,7 @@
 path.close();
 
     SkPath path2(path);
-    testPathOpSkipAssert(reporter, path1, path2, (SkPathOp) 0, filename);
+    testPathOpFlakySkipAssert(reporter, path1, path2, (SkPathOp) 0, filename);
 }
 
 static void fuzz763_20(skiatest::Reporter* reporter, const char* filename) {