Update survey proto to support data sharing agreement

proto/src/google/ground/v1beta1/survey.proto

@@ -37,6 +37,18 @@ message Survey {
 
   // Required. User id of the survey owner.
   string owner_id = 5;
+
+  // Properties related to data sharing consent.
+  message DataSharingConsent {
+    // Type of data sharing consent agreement the user will see.
+    DataSharingConsentType type = 1;
+
+    // Text of custom data sharing consent terms.
+    string custom_text = 2;
+  }
+
+  // Defines how data sharing consent agreemnent is displayed to users.
+  DataSharing dataSharingConsent = 6;
 }
 
 // Defines a user's role in a survey.
@@ -53,3 +65,15 @@ enum Role {
   // User may also manage the survey, update locations of interest, etc.
   SURVEY_ORGANIZER = 3;
 }
+
+// Defines the type of data sharing consent agreement the user can see.
+enum DataSharingConsentType {
+  // Data will only be shared with survey organizers.
+  PRIVATE = 0;
+
+  // Survey organizers can share data with no constraints.
+  PUBLIC = 1;
+
+  // Terms are defined by survey organizers.
+  CUSTOM = 2;
+}