Turn AOM_QM_EXT on by default

This tool is provisionally adopted.

Change-Id: I198bd2a986f05c898a8e3bb91efe018fc6e74358

build/cmake/aom_config_defaults.cmake

diff --git a/build/cmake/aom_config_defaults.cmake b/build/cmake/aom_config_defaults.cmake
index b0edb7b..37cfa76 100644
--- a/build/cmake/aom_config_defaults.cmake
+++ b/build/cmake/aom_config_defaults.cmake
@@ -88,7 +88,7 @@
 
 # AV1 experiment flags.
 set(CONFIG_AMVR 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_AOM_QM_EXT 0 CACHE NUMBER "AV1 experiment flag.")
+set(CONFIG_AOM_QM_EXT 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_CDF_UPDATE_MODE 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_CFL 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_DEPENDENT_HORZTILEGROUPS 0 CACHE NUMBER "AV1 experiment flag.")