command: Respect smart sync override declaratively by default

Introduce a `RESPECT_SMART_SYNC_OVERRIDE` class attribute to the base
`Command` class, defaulting to `True`. This allows subcommands to
automatically respect the smart sync override manifest if it exists.

The override is applied in `CommonValidateOptions` before any
subcommand-specific validation or execution occurs. The `sync` and
`init` commands explicitly opt out.

This ensures all workspace-aware subcommands consistently align with the
active smart sync override manifest. It also fixes a bug in
multi-manifest setups where running a command from a submanifest would
not apply the override to the outer manifest, causing inconsistency when
resolving projects across all manifests.

Bug: 279204331
Change-Id: I9426e90a13a77ce6bd94b4a82efda4d485cbe116
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/585081
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>

command.py

@@ -66,6 +66,10 @@ class Command:
     # command to show short-vs-full summaries.
     COMMON = False
 
+    # Whether this command should respect the smart sync override manifest if
+    # it exists.
+    RESPECT_SMART_SYNC_OVERRIDE = True
+
     # Whether this command supports running in parallel. If greater than 0,
     # it is the number of parallel jobs to default to.
     PARALLEL_JOBS = None
@@ -247,6 +251,12 @@ class Command:
             # from the user's perspective.
             opt.outer_manifest = True
 
+        if self.RESPECT_SMART_SYNC_OVERRIDE:
+            if self.manifest:
+                self.TryOverrideManifestWithSmartSync(self.manifest)
+            if self.outer_manifest and self.outer_manifest != self.manifest:
+                self.TryOverrideManifestWithSmartSync(self.outer_manifest)
+
     def ValidateOptions(self, opt, args):
         """Validate the user options & arguments before executing.