Increase active map test coverage from RT speeds 0-5 to 0-8.

This test takes less than 100 ms for each of speeds 6-8.

Change-Id: Ibbeb3004a2607d25dcbf77cb5314ade87809e059

test/active_map_test.cc

@@ -85,5 +85,5 @@ TEST_P(ActiveMapTest, Test) {
 
 VP9_INSTANTIATE_TEST_CASE(ActiveMapTest,
                           ::testing::Values(::libvpx_test::kRealTime),
-                          ::testing::Range(0, 6));
+                          ::testing::Range(0, 9));
 }  // namespace