Enable Configurable Profiler Output Formats

[darklight3it]

Enable Configurable Profiler Output Formats

This PR adds support for configurable profiler start/stop commands in the AWS Lambda Java Profiler extension, allowing users to customize the profiling output format and behavior.

Changes

New Constants.java

• Introduces environment variable support for profiler commands:
  • AWS_LAMBDA_PROFILER_START_COMMAND - customize the async-profiler start command (default: start,event=wall,interval=1us)
  • AWS_LAMBDA_PROFILER_STOP_COMMAND - customize the async-profiler stop command (default: stop,file=%s,include=*AWSLambda.main,include=start_thread)
• Adds getFilePathFromEnv() to extract the output file path from the start command

Updated PreMain.java

• Refactored to use the new Constants class for profiler commands
• Enables users to specify different output formats (HTML, JFR, collapsed stacks, etc.) via environment variables

Usage

Users can now configure the profiler output by setting environment variables:

# Example: Output as JFR format instead of HTML
AWS_LAMBDA_PROFILER_START_COMMAND="start,event=wall,interval=1us,file=/tmp/profile.jfr"
AWS_LAMBDA_PROFILER_STOP_COMMAND="stop,file=%s"

[maxday]

Awesome! Thanks for adding testing too