Update MASTG-DEMO-0006 to cover the remaining MASTG-TEST-0203 logging APIs

Following up on discussion #3948, where @cpholguera suggested updating MASTG-DEMO-0006 before adding a new static demo for MASTG-TEST-0231.

Context

MASTG-TEST-0203 lists the following APIs: apis: [Log, Logger, System.out.print, System.err.print, java.lang.Throwable#printStackTrace]

MASTG-DEMO-0006 is currently its only demo. From what I can see, MastgTest.kt covers android.util.Log (v, i, w, d, e, wtf) and java.util.logging.Logger.severe, while run.sh hooks android.util.Log!* and java.util.logging.Logger!severe.

The API's that are not covered yet:

• System.out.print / println
• System.err.print / println
• Throwable.printStackTrace

Proposed change:

1. Add samples for the three APIs above to MastgTest.kt
2. Extend the hooks to java.io.PrintStream!print* and java.lang.Throwable!printStackTrace* (System.out and System.err are both PrintStream instances)
3. Regenerate output.txt and logcat_output.txt from a real run
4. Update the Steps / Observation / Evaluation sections to match

A few scope questions:

1. Tooling: Should this stay with frida-trace or migrate to frooky + hooks.json? The current demo instructions prefer frooky, and filterEventsByStacktrace looks useful for reducing the noise from hooking java.io.PrintStream.
2. Demo Conventions: MastgTest.kt has no // SUMMARY: comment and no // FAIL: [MASTG-TEST-0203] annotations. Should I bring it in line with the current demo instructions here, or keep the diff minimal?
3. Terminology: The demo title currently uses "...Looking for Secrets", while draft PR #3592 changes the terminology in this area toward "authenticators". Should this update stay aligned with the current master, or follow the wording from that PR?

I would like to work on this. Happy to be assigned.