Add support to use GNU sed installed in mac osx (#770)

* Add support to use GNU sed installed in mac osx

* Move common functions to utils.sh

Co-authored-by: Swinder Pal Singh Juneja <swinder.juneja@oneplus.com>

update_settings.sh

@@ -3,18 +3,8 @@ DEFAULT_FALSE="'default': false"
 TELEMETRY_ENABLE="'telemetry.enableTelemetry':"
 TELEMETRY_CRASH_REPORTER="'telemetry.enableCrashReporter':"
 
-is_gnu_sed () {
-  sed --version >/dev/null 2>&1
-}
-
-replace () {
-  echo $1
-  if is_gnu_sed; then
-    sed -i -E "$1" $2
-  else
-    sed -i '' -E "$1" $2
-  fi
-}
+#include common functions
+. ../utils.sh
 
 update_setting () {
   local FILENAME="$2"