Stripped unneeded deps from Android gradle. Reduced apk size.

Author: pauldemarco

android/build.gradle

@@ -8,7 +8,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.1'
+        classpath 'com.android.tools.build:gradle:3.1.3'
         classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.3'
     }
 }
@@ -39,7 +39,7 @@ android {
     dependencies {
         // Required for local unit tests (JUnit 4 framework)
         testImplementation 'junit:junit:4.12'
-        implementation 'com.android.support:support-v4:27.1.0'
+        implementation 'com.android.support:support-compat:27.1.1'
         //compile files('/home/paul/flutter/bin/cache/artifacts/engine/android-arm/flutter.jar')
     }
     sourceSets {
@@ -55,7 +55,7 @@ protobuf {
     // Configure the protoc executable
     protoc {
         // Download from repositories
-        artifact = 'com.google.protobuf:protoc:3.0.0'
+        artifact = 'com.google.protobuf:protoc:3.6.1'
     }
     plugins {
         javalite {
@@ -73,6 +73,5 @@ protobuf {
 }
 
 dependencies {
-    implementation 'com.google.protobuf:protobuf-lite:3.0.0'
-    implementation group: 'com.google.guava', name: 'guava', version: '22.0-android'
+    implementation 'com.google.protobuf:protobuf-lite:3.0.1'
 }