Bump manifest-merger from 30.3.0 to 30.3.1 in /src/manifestmerger (do…

…tnet#7467)

Context: https://mvnrepository.com/artifact/com.android.tools.build/manifest-merger/30.3.1
Context: https://android.googlesource.com/platform/tools/base/+/master/build-system/manifest-merger

There was [a point in time][0] where 30.3.1 was giving a 404 on maven, but it appears to be there now.

[0]: dotnet#7467 (comment)

src/manifestmerger/build.gradle

@@ -19,7 +19,7 @@ repositories {
 
 dependencies {
     // https://mvnrepository.com/artifact/com.android.tools.build/manifest-merger
-    compile group: 'com.android.tools.build', name: 'manifest-merger', version: '30.3.0'
+    compile group: 'com.android.tools.build', name: 'manifest-merger', version: '30.3.1'
 }
 
 sourceSets {