Increase thread timeout to reduce flakiness.

Taken from upstream:
https://github.com/xbmc/xbmc/commit/574b0182d8b641fd24029f372ebdcccc897123e2

diff --git a/xbmc/threads/test/TestEvent.cpp b/xbmc/threads/test/TestEvent.cpp
index 42fb8c2fc609..40e644c0ed3c 100644
--- a/xbmc/threads/test/TestEvent.cpp
+++ b/xbmc/threads/test/TestEvent.cpp
@@ -484,7 +484,7 @@ TEST(TestEvent, GroupTimedWait)
   EXPECT_TRUE(w3.result == NULL);
 
   // this should end given the wait is for only 50 millis
-  EXPECT_TRUE(waitThread3.timed_join(MILLIS(100)));
+  EXPECT_TRUE(waitThread3.timed_join(MILLIS(200)));
 
   EXPECT_TRUE(!w3.waiting);
   EXPECT_TRUE(w3.result == NULL);
