[build] update gradle-errorprone-plugin to 1.1.0

Problem
The plugin for error-prone is out of date

Solution
Update the plugin.

build.gradle

@@ -7,7 +7,7 @@ buildscript {
 
     dependencies {
         classpath 'gradle.plugin.nl.javadude.gradle.plugins:license-gradle-plugin:0.14.0'
-        classpath 'net.ltgt.gradle:gradle-errorprone-plugin:0.6'
+        classpath 'net.ltgt.gradle:gradle-errorprone-plugin:1.1.0'
 
         //Using buildscript.classpath so that we can resolve shipkit from maven local, during local testing
         classpath 'org.shipkit:shipkit:2.1.6'

gradle/errorprone.gradle

@@ -12,5 +12,5 @@ dependencies {
 }
 
 tasks.named("compileTestJava").configure {
-    options.errorprone.errorproneArgs << "-Xep:MockitoCast:OFF"
+    options.errorprone.errorproneArgs.add("-Xep:MockitoCast:OFF")
 }