Rename sharesheet started atom proto fields.

When copying over the fields into Google3 the linter failed on two field
names that are camel case rather than snake case. Changing here so the
two match. In addition, one of the enum fields didn't have a default
value.

Bug: 147508495
Test: compiles + ChooserActivityTest runs
Change-Id: Iacec9654350763e691a4a10087f693839fd5ea83
diff --git a/cmds/statsd/src/atoms.proto b/cmds/statsd/src/atoms.proto
index 453ddeb..1f090fd 100644
--- a/cmds/statsd/src/atoms.proto
+++ b/cmds/statsd/src/atoms.proto
@@ -9249,12 +9249,13 @@
     optional bool is_workprofile = 7;
 
     enum SharesheetPreviewType {  // Constants from ChooserActivity.java
+        CONTENT_PREVIEW_TYPE_UNKNOWN = 0;  // Default for proto 2 / 3 compatibility.
         CONTENT_PREVIEW_IMAGE = 1;  // The preview shown in the sharesheet is an image.
         CONTENT_PREVIEW_FILE = 2;  // The preview shown in the sharesheet is a file.
         CONTENT_PREVIEW_TEXT = 3;  // The preview shown in the sharesheet is text.
     }
     // How the sharesheet preview is presented.
-    optional SharesheetPreviewType previewType = 8;
+    optional SharesheetPreviewType preview_type = 8;
 
     enum ResolverActivityIntent { // Intents handled by ResolverActivity.java
         INTENT_DEFAULT = 0;
@@ -9267,7 +9268,7 @@
         INTENT_ACTION_MAIN = 7;
     }
     // The intent being processed (only SEND and SEND_MULTIPLE are system sharesheet)
-    optional ResolverActivityIntent intentType = 9;
+    optional ResolverActivityIntent intent_type = 9;
 }
 
 /**