https://wccftech.com/pixel-5-features-reverse-wireless-charging-android-11-menu/

With Google releasing the first Android 11 Developer Preview for Pixel smartphones, which doesn’t include the first-generation Pixel models, it didn’t take long for XDA Developers to discover what could be one of the several Pixel 5 features. While digging into the Android 11 system dump for the Pixel 4, Mishaal Rahman came across a ‘Battery Share’ menu. Launching the activity revealed that Google might be working on reverse wireless charging for the upcoming Pixel 5 and Pixel 5 XL.

The activity name was shown as ‘com.google.android’ instead of ‘com.android’. XDA later hints that due to this little, but important change, it’s possible that the ‘Battery Share’ activity is most likely exclusive for the Pixel 5 series. Also, Android 11’s Battery Share menu had this important bit mentioned, implying that one of the Pixel 5 features might include reverse wireless charging.