Add Conditional Extraction of ApplicationExitInfo Trace Data for Enhanced Logging

[jaredsburrows]

Closes #90

@murki

This PR updates the ApplicationExitInfo.toFields() function to conditionally extract and include trace data in the app termination log when available. Previously, only basic application exit information was logged. Now, the trace data field (_app_exit_trace) will be included in the metadata when a relevant exit reason and non-empty trace data exist.

This change improves the accuracy and usefulness of app termination logs by only including trace data when meaningful, specifically for ANR and native crash scenarios. By avoiding the addition of empty or irrelevant trace data, this update enhances the quality of diagnostics information for developers.

Refactored ApplicationExitInfo.toFields():

• Converted the toFields function from using a direct mapOf to initializing a mutable map (fields), enabling conditional addition of _app_exit_trace.
• Added logic to check if ApplicationExitInfo.reason is either REASON_ANR or REASON_CRASH_NATIVE. If so, getTraceInputStream() is called to retrieve any available trace data.

Conditional Trace Data Extraction:

• Used getTraceInputStream() with a check on traceStream.available() to ensure only non-empty streams are processed.
• _app_exit_trace is added to the fields map only when valid trace data is found, avoiding unnecessary empty fields in the log.

Improved Logging Precision:

• Ensures that trace data is only included in the event log when relevant and available, reducing noise in the logs and improving clarity in app exit event reporting.

References:

• https://developer.android.com/reference/android/app/ApplicationExitInfo#getTraceInputStream()
• https://developer.android.com/ndk/guides/debug#tombstone-traces

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[jaredsburrows]

I have read the CLA Document and I hereby sign the CLA.

[murki]

according to the docs: "tombstone traces will be returned for REASON_CRASH_NATIVE, with an InputStream containing a protobuf with [this schema]"(https://android.googlesource.com/platform/system/core/+/refs/heads/master/debuggerd/proto/tombstone.proto)

we should parse the stream using that proto and extract its properties individually

[jaredsburrows]

We can generate the parseFrom Tombestone by adding the proto do this repo. We would need to keep tombstone.proto up to date to have the latest fields to parse the inputstream.

[murki]

@jaredsburrows were you able to test this in the wild? If so it would be helpful to link to a session that can be verified

[murki]

Another thing I noticed from the docs:

Note that because these traces are kept in a separate global circular buffer, crashes may be overwritten by newer crashes (including from other applications)

Something else that we might need to think about if and how to handle