update_engine: Deprecate minor version 1

Minor version 1 was for the old days where we rewrite the signle
partition with an update (no A/B partitions). But those days are long
over and we don't think there is any device out that has this capability
anymore. Even if there is, we can always serve full payloads along with
the stepping stone we have in M53. So this is safe to go.

BUG=chromium:1008553
TEST=sudo FEATURES=test emerge update_engine
TEST=ran cros flash two times.

Change-Id: Ib928ade36af5136cd4013a30dfb39ee7fd5b07b1
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/1829160
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Sen Jiang <senj@chromium.org>
Commit-Queue: Amin Hassani <ahassani@chromium.org>
diff --git a/update_metadata.proto b/update_metadata.proto
index b0e8154..3382f84 100644
--- a/update_metadata.proto
+++ b/update_metadata.proto
@@ -153,10 +153,10 @@
 
 message InstallOperation {
   enum Type {
-    REPLACE = 0;  // Replace destination extents w/ attached data
-    REPLACE_BZ = 1;  // Replace destination extents w/ attached bzipped data
-    MOVE = 2;  // Move source extents to destination extents
-    BSDIFF = 3;  // The data is a bsdiff binary diff
+    REPLACE = 0;     // Replace destination extents w/ attached data.
+    REPLACE_BZ = 1;  // Replace destination extents w/ attached bzipped data.
+    MOVE = 2 [deprecated = true];    // Move source extents to target extents.
+    BSDIFF = 3 [deprecated = true];  // The data is a bsdiff binary diff.
 
     // On minor version 2 or newer, these operations are supported:
     SOURCE_COPY = 4; // Copy from source to target partition