IssueTracker

* Which Developer Preview build are you using? See Settings > About phone > Build number (for example OPP5.170921.005).
PPP3.180510.008

    * Is this a regression from O to P?
Not sure

    * What device are you using? (for example, Pixel XL)
Pixel 2

All information is written here:
https://issuetracker.google.com/issues/110285356

I will try to summarize. It's actually 3 issues:

1. Getting 2 intents for all state-change events of calls, even for events that are not supposed to be this way. This includes these states: RINGING , IDLE , OFFHOOK .
According to the docs, only RINGING state can be called twice:
https://developer.android.com/reference/android/telephony/TelephonyManager#ACTION_PHONE_STATE_CHANGED
If you try with other Android devices and versions (even those of Google), you will see it's actually always a single call, that has the phone number.

2. For RINGING state, we get 2 calls, but it's the opposite of  what's written in the docs:
https://developer.android.com/reference/android/telephony/TelephonyManager#ACTION_PHONE_STATE_CHANGED
" it will receive the broadcast twice; one with the phone number and another without it."

It's not the first that has the phone number. Only the second. This makes it impossible to know for sure if the phone number is a private number (null), because there are 2 cases now:
2 calls. One with null and second with phone number (or null in case it's really a private number).
1 call which just has null (private number).
Because of these 2 different behaviors on devices, the only workaround I've found is that if I get null, I wait a bit (100ms) to decide whether it's indeed a private number or not.

The order should be as described in the docs, meaning first call should provide the phone number.

3. When not having READ_CALL_LOG permission, we have a single call to the intent (which is ok according to the docs), but the EXTRA_INCOMING_NUMBER is never non-null. The docs don't write about this. In fact, it's written that it should have the phone number. It also doesn't make sense.
https://developer.android.com/reference/android/telephony/TelephonyManager.html#EXTRA_INCOMING_NUMBER


Changing the targetSdk to lower than 28 doesn't make it consistent. This inconsistent behavior seem to be Android P only.