fix(deps): update dependency com.google.api:gax-grpc to v2.70.1

Author: renovate-bot

build.gradle

@@ -110,7 +110,7 @@ dependencies {
 
     // For Spanner mock server testing
     testImplementation(group: 'com.google.cloud', name: 'google-cloud-spanner', classifier: 'tests')
-    testImplementation(group: 'com.google.api', name: 'gax-grpc', version: '2.69.0', classifier: 'testlib')
+    testImplementation(group: 'com.google.api', name: 'gax-grpc', version: '2.70.1', classifier: 'testlib')
 
     // For Liquibase to work without throwing NoClassDefFound/NoSuchMethodError
     testRuntimeOnly("info.picocli:picocli:4.7.7")