Get off my lawn forever!

Let folks opt in if they want the custom title.

Bug: https://issuetracker.google.com/38402256
Test: hitting enter no longer flashes this title
Change-Id: I8c1e1b22cc47ab9496797328fb1b13c0827840b0
diff --git a/envsetup.sh b/envsetup.sh
index 9a616ef..394df65 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -318,7 +318,12 @@
 
 function settitle()
 {
-    if [ "$STAY_OFF_MY_LAWN" = "" ]; then
+    # This used to be opt-out with STAY_OFF_MY_LAWN, but this breaks folks
+    # actually using PROMPT_COMMAND (https://issuetracker.google.com/38402256),
+    # and the attempt to set the title doesn't do anything for the default
+    # window manager in debian right now, so switch it to opt-in for anyone
+    # who actually wants this.
+    if [ "$ANDROID_BUILD_SET_WINDOW_TITLE" = "true" ]; then
         local arch=$(gettargetarch)
         local product=$TARGET_PRODUCT
         local variant=$TARGET_BUILD_VARIANT