Bump mavsdk to 0.3.1 and update proto submodule

JonasVautherin · JonasVautherin · commit 4ef7dac9a9bf · 2020-05-11T17:20:27.000+02:00
diff --git a/sdk/build.gradle b/sdk/build.gradle
@@ -17,7 +17,7 @@ subprojects {
 
     group = 'io.mavsdk'
     archivesBaseName = 'mavsdk'
-    version = '0.3.0'
+    version = '0.3.1'
 
     repositories {
         jcenter()
diff --git a/sdk/proto b/sdk/proto
@@ -1 +1 @@
-Subproject commit e82aad46dcd3746634911c474734128b52e8d3c7
+Subproject commit 6dfc90966e782ee7faf55f620f2cb7d1b736d79d
