Update to protobuf 3.10 lite.

java/build.gradle

@@ -1,4 +1,16 @@
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.10'
+    }
+}
+
 apply plugin: 'java'
+apply plugin: 'com.google.protobuf'
 apply plugin: 'maven'
 apply plugin: 'signing'
 
@@ -13,7 +25,7 @@ repositories {
 }
 
 dependencies {
-    compile 'com.google.protobuf:protobuf-java:2.5.0'
+    compile 'com.google.protobuf:protobuf-javalite:3.10.0'
     compile 'com.googlecode.libphonenumber:libphonenumber:8.10.7'
     compile 'com.fasterxml.jackson.core:jackson-databind:2.9.9.2'
 
@@ -32,6 +44,24 @@ tasks.whenTaskAdded { task ->
     }
 }
 
+protobuf {
+    protoc {
+        artifact = 'com.google.protobuf:protoc:3.10.0'
+    }
+    generateProtoTasks {
+        all().each { task ->
+            task.builtins {
+                java {
+                    option "lite"
+                }
+            }
+        }
+    }
+}
+
+sourceSets {
+    main.proto.srcDir '../protobuf'
+}
 
 def isReleaseBuild() {
     return version.contains("SNAPSHOT") == false

protobuf/Makefile

@@ -1,3 +0,0 @@
-
-all:
-	protoc --java_out=../java/src/main/java/ SignalService.proto Provisioning.proto WebSocketResources.proto StickerResources.proto

protobuf/Provisioning.proto

@@ -3,10 +3,11 @@
  *
  * Licensed according to the LICENSE file in this repository.
  */
+syntax = "proto2";
 
 package signalservice;
 
-option java_package = "org.whispersystems.signalservice.internal.push";
+option java_package         = "org.whispersystems.signalservice.internal.push";
 option java_outer_classname = "ProvisioningProtos";
 
 message ProvisionEnvelope {

protobuf/SignalService.proto

@@ -3,10 +3,11 @@
  *
  * Licensed according to the LICENSE file in this repository.
  */
+syntax = "proto2";
 
 package signalservice;
 
-option java_package = "org.whispersystems.signalservice.internal.push";
+option java_package         = "org.whispersystems.signalservice.internal.push";
 option java_outer_classname = "SignalServiceProtos";
 
 message Envelope {

protobuf/StickerResources.proto

@@ -3,10 +3,11 @@
  *
  * Licensed according to the LICENSE file in this repository.
  */
+syntax = "proto2";
 
 package signalservice;
 
-option java_package = "org.whispersystems.signalservice.internal.sticker";
+option java_package         = "org.whispersystems.signalservice.internal.sticker";
 option java_outer_classname = "StickerProtos";
 
 message Pack {

protobuf/WebSocketResources.proto

@@ -3,10 +3,11 @@
  *
  * Licensed according to the LICENSE file in this repository.
  */
+syntax = "proto2";
 
 package signalservice;
 
-option java_package = "org.whispersystems.signalservice.internal.websocket";
+option java_package         = "org.whispersystems.signalservice.internal.websocket";
 option java_outer_classname = "WebSocketProtos";
 
 message WebSocketRequestMessage {