Fix comments for SeparateArguments and ExtractCvdArgs

Bug: b/389804379
Test: /usr/bin/bazel run :cvd -- --instance_name=1 status

Author: Databean

base/cvd/cuttlefish/host/commands/cvd/cli/frontline_parser.cpp

@@ -34,18 +34,6 @@ namespace cuttlefish {
 using selector::SeparateArguments;
 using selector::SeparatedArguments;
 
-/* the very first command line parser
- *
- * Being aware of valid subcommands and cvd-specific commands, it will
- * separate the command line arguments into:
- *
- *  1. program path/name
- *  2. cvd-specific arguments
- *     a) selector flags
- *     b) non-selector flags
- *  3. subcommand
- *  4. subcommand arguments
- */
 Result<cvd_common::Args> ExtractCvdArgs(cvd_common::Args& args) {
   CF_EXPECT(!args.empty());
 

base/cvd/cuttlefish/host/commands/cvd/cli/selector/arguments_separator.h

@@ -49,23 +49,8 @@ struct SeparatedArguments {
  *  $ program_path/name <optional cvd-specific flags> \
  *                      subcmd <optional subcmd arguments>
  *
- * For the parser's sake, there are a few more rules.
+ * For the parser's sake, there are is another rule.
  *
- * 1. All the optional cvd-specific flags should be pre-registered. Usually,
- * the subcmd arguments do not have to be registered. However, cvd-specific
- * flags must be.
- *
- *  E.g. "--clean" is the only registered cvd-specific flag, which happened
- *      to be bool.
- *       These are okay:
- *         cvd --clean start --never-exist-flag
- *         cvd --noclean stop
- *         cvd start
- *
- *       However, this is not okay:
- *        cvd --daemon start
- *
- *  2. --
  *  E.g. cvd --clean start --have --some --args -- a b c d e
  *  -- is basically for subcommands. cvd itself does not use it.
  *  If -- is within cvd arguments, it is ill-formatted. If it is within