[location_background] Ignore for CI (firebase#1890)

This pacakge should be removed entirely soon, so remove it from CI so we
don't spend further time on analyzer failures.

script/common.sh

@@ -24,11 +24,12 @@ function check_changed_packages() {
   fi
 
   # Filter out any packages that don't have a pubspec.yaml: they have probably
-  # been deleted in this PR.
+  # been deleted in this PR. Also filter out `location_background` since it
+  # should be removed soon.
   CHANGED_PACKAGES=""
   CHANGED_PACKAGE_LIST=()
   for package in "${packages[@]}"; do
-    if [[ -f "$REPO_DIR/packages/$package/pubspec.yaml" ]]; then
+    if [ -f "$REPO_DIR/packages/$package/pubspec.yaml" ] && [ $package != "location_background" ]; then
       CHANGED_PACKAGES="${CHANGED_PACKAGES},$package"
       CHANGED_PACKAGE_LIST=("${CHANGED_PACKAGE_LIST[@]}" "$package")
     fi