Add heartbeat notifications

[lukeswitz]

Feature Description:

Updated

Fills feature request from #54

• Option to send beating heart emoji while the monitor is active.
• Timer settings: minimum 1 minute and defaults to 5.
• Sent to the saved phone number via Signal as: 💓
• Used JNI compatible strings to avoid parsing errors on lower Android versions instead of adding the EmojiCompat dependency

[n8fr8]

Excellent, so happy to see this work underway!

[n8fr8]

In quick testing, it seems to send the heartbeat when the app is open, not just when there is an active monitoring session. Is that the case? I will look through the code more, but just curious what your intention was.

[lukeswitz]

Thanks, that was the intent, to make sure the app is still alive. I didn't hook into any service/activity; when testing, the leaked handler would cease alerts but keep monitoring locally. Your help & thoughts on where/when to monitor are very much appreciated : )

[n8fr8]

In talking with some of our most committed users, they sometimes have incidents where they forget whether they have activated Haven or not. To them the heartbeat, was a way to confirm that active monitoring was engaged, and if it stopped, to know that someone had turned it off. I would tie this all into the Monitor Service to enable that.

[lukeswitz]

On it.

[n8fr8]

Cool. Will review soon!