rdk: Replace hardcoded blocked_flags with generic flag deduplication in deploy_rdk

[niranjanyardi]

Summary

Replaces the hardcoded blocked_flags set in deploy_rdk.py with generic key-based CLI switch deduplication.

When launching Cobalt on device as a WPEFramework plugin, existing sbmainargs are retrieved via JSON-RPC. If --devtools or new arguments via --param (e.g. --enable-heap-profiling, --memlog=all, --trace-startup=...) are passed, appending them directly to sbmainargs can result in duplicate switches and startup parsing failures.

Rather than maintaining a hardcoded blacklisted set of switch names (blocked_flags) that must be expanded manually whenever new flags are used, this change dynamically extracts all flag keys (arg.split("=", 1)[0]) from the parameters being added and strips any pre-existing matching flags from sb_args prior to extending.

Motivation & Architecture

• Avoids Infinite Flag Blacklists: Eliminates the need to modify deploy_rdk.py whenever someone wants to pass --v=1, --fps, --user-agent, or future profiling/tracing parameters.
• Strict Long-Switch Scoping (--): Uses arg.startswith("--") to safely match Chromium/Cobalt double-dash switches without risking collision with negative positional arguments or non-flag parameters.

Verification

• Verified argument filtering behavior when overriding --remote-debugging-port and --param flags.
• Checked git branch rebased against latest origin/main.

Bug: 502702565

TAG=agy
CONV=073fedec-c1e0-47a6-bc41-c69a0d7df7ab

[github-actions]

🤖 Gemini Suggested Commit Message

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starboard: Deduplicate flags in deploy_rdk

Update the RDK deployment script to support generic de-duplication of
command line arguments. This ensures that flags provided through
command line parameters correctly override default settings without
leaving duplicate or conflicting arguments in the final execution
string. This improvement simplifies debugging by allowing flexible
parameter overrides and includes usage examples for heap profiling.

Bug: 11531

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[gemini-code-assist]

Code Review

This pull request updates the command-line argument handling in deploy_rdk.py to dynamically filter out existing arguments in sb_args that are overridden by new_args, replacing a hardcoded list of blocked flags. The review feedback points out two potential issues with the standard double-dash ("--") separator: first, "--" should be excluded from the override keys to prevent it from being filtered out, and second, new arguments should be inserted before the "--" separator rather than appended to the end, ensuring they are not incorrectly treated as positional arguments.