Android ExampleApp's jni `build.sh` doesn't handle relative pathes for LOG_FILE

[muzso]

Describe the bug

The <sdk>/examples/android/ExampleApp/app/src/main/jni/build.sh script redirects various command output into $LOG_FILE, but meanwhile it changes the current working directory multiple times.

Thus if we specify a relative path for the LOG_FILE variable, build.sh will create a number of logfiles in a number of directories.

This is most certainly not the expected behaviour.

The <sdk>/examples/android/ExampleApp/README.md file only says the following:

If you want a more verbose output to inspect the output looking for build errors, change the LOG_FILE variable in the build.sh script from /dev/null to /dev/stdout or to a file like /tmp/build.log

This doesn't imply (yet) that using an absolute path is mandatory (or else ...).

To Reproduce

Steps to reproduce the behavior:

1. Checkout sdk repo.
2. Change current working directory to <sdk>/examples/android/ExampleApp/app/src/main/jni.
3. Run LOG_FILE=log.txt build.sh all

Expected behavior

Only one logfile is created.

Ideally if the value given to LOG_FILE doesn't start with a /, the current working directory should be prepended.

Currently LOG_FILE is initialized like this:

if [ -z "${LOG_FILE}" ]; then
    # If no build log variable is defined, use below value.
    LOG_FILE=/dev/null # Ensure you use a full path
fi

Instead it should be something like this:

if [ -z "${LOG_FILE}" ]; then
    # If no build log variable is defined, use below value.
    LOG_FILE=/dev/null # Ensure you use a full path
elsif [ "${LOG_FILE:0:1}" != "/" ]; then
    LOG_FILE="$(pwd)/$LOG_FILE"
fi

If this is not a desired solution, the README.md should explicitly say that an absolute path should be used, or there'll be a number of logfiles created throughout the tree of the <sdk>/examples/android/ExampleApp/app/src/main/jni directory.

Screenshots

I don't think this is necessary, since the bug/issue (and a potential fix) is well described. And it's trivially reproducible.

Environment:

• SDK Version: v9.16.1
• OS: Ubuntu 22.04.5 LTS
• Device: Android

Additional context

No additional context.