Suggest developers use -eng builds instead when they lunch -userdebug

This is because -eng provides faster local builds.

(also moving hints to where they are more likely to be seen)

Test: lunch cf_x86_64_phone-userdebug
Fixes: 307753064
Change-Id: I52cf9e9c399dbb3a52c7952f7204a9e567d15c22

envsetup.sh

@@ -848,15 +848,21 @@ function lunch()
     fi
     export TARGET_BUILD_TYPE=release
 
+    [[ -n "${ANDROID_QUIET_BUILD:-}" ]] || echo
+
+    set_stuff_for_environment
+    [[ -n "${ANDROID_QUIET_BUILD:-}" ]] || printconfig
+
+    if [ "${TARGET_BUILD_VARIANT}" = "userdebug" ] && [[  -z "${ANDROID_QUIET_BUILD}" ]]; then
+      echo
+      echo "Want FASTER LOCAL BUILDS? Use -eng instead of -userdebug (however for" \
+        "performance benchmarking continue to use userdebug)"
+    fi
     if [ $used_lunch_menu -eq 1 ]; then
       echo
       echo "Hint: next time you can simply run 'lunch $selection'"
     fi
 
-    [[ -n "${ANDROID_QUIET_BUILD:-}" ]] || echo
-
-    set_stuff_for_environment
-    [[ -n "${ANDROID_QUIET_BUILD:-}" ]] || printconfig
     destroy_build_var_cache
 
     if [[ -n "${CHECK_MU_CONFIG:-}" ]]; then