Move FileStateValue.Type to Metadata; add Metadata.getType()

This is in preparation for merging FileArtifactValue and FileStateValue.

Progress on #3360.

PiperOrigin-RevId: 179832948
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactBuildTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactBuildTest.java
index 6c15a1f..e0bb1f7 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactBuildTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactBuildTest.java
@@ -158,8 +158,8 @@
             try {
               // Check the file cache for input TreeFileArtifacts.
               ActionInputFileCache fileCache = actionExecutionContext.getActionInputFileCache();
-              assertThat(fileCache.getMetadata(outOneFileOne).isFile()).isTrue();
-              assertThat(fileCache.getMetadata(outOneFileTwo).isFile()).isTrue();
+              assertThat(fileCache.getMetadata(outOneFileOne).getType().isFile()).isTrue();
+              assertThat(fileCache.getMetadata(outOneFileTwo).getType().isFile()).isTrue();
 
               // Touch the action output.
               touchFile(normalOutput);