Suppress AnnotationLocation checkstyle rule

This rule flags valid usages because it conflates annotated methods and
annotated return types, considering that the `@Nullable` annotation
should be on its own line. For example, the following fails:

```
@Override
@Nullable String getName() {
```

See gh-1132

src/checkstyle/checkstyle-suppressions.xml

@@ -8,6 +8,8 @@
 
 	<!-- main -->
 	<suppress files="[\\/]src[\\/]main[\\/]java[\\/]" checks="SpringMethodVisibility" />
+	<!-- Ignore this check for @Nullable annotations -->
+	<suppress files="[\\/]src[\\/]main[\\/]java[\\/]" checks="AnnotationLocation" />
 
 	<!-- tests -->
 	<suppress files="[\\/]src[\\/]testFixtures[\\/]java[\\/]" checks="JavadocPackage|SpringJavadoc" />