Revert node version in yaml changes (#823)

Author: barnesjoseph

.github/workflows/build.yml

@@ -31,7 +31,7 @@ jobs:
     strategy:
       matrix:
         node-version:
-          - 18.x
+          - 16.x
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3

.github/workflows/test.yml

@@ -27,7 +27,7 @@ jobs:
     strategy:
       matrix:
         node-version:
-          - 18.x
+          - 16.x
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3

app/app.yaml

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-runtime: nodejs18
+runtime: nodejs16
 handlers:
 # Serve all static files with url ending with a file extension
 - url: /(.*\..+)$