Disable Gallery drawer content when closed

[chrisglein]

Description

Why

When you tab through Gallery, you hit the closed drawer items. Those items should not be keyboard focusable.

Related to #408

What

Removed the drawer content entirely when the drawer is in the closed state.
Additionally changed the drawer mode to not be "permanent", which didn't seem to be the cause here but also doesn't seem to be necessary.

Screenshots

Here is gallery with the fix:
https://github.com/microsoft/react-native-gallery/assets/26607885/fcf25e92-450d-4627-8f4d-c8027e3a8f88

[Yajur-Grover]

Tested it locally - looks like there's still one phantom tab stop now on the home page: https://microsoft-my.sharepoint-df.com/:v:/p/yajurgrover/EY3otnRX6_tKu9cnSEYDMkkBdxn69UquorPhvm6M5LkdfA?e=yVEeMi&nav=eyJyZWZlcnJhbEluZm8iOnsicmVmZXJyYWxBcHAiOiJTdHJlYW1XZWJBcHAiLCJyZWZlcnJhbFZpZXciOiJTaGFyZURpYWxvZy1MaW5rIiwicmVmZXJyYWxBcHBQbGF0Zm9ybSI6IldlYiIsInJlZmVycmFsTW9kZSI6InZpZXcifX0%3D

From the focusable warning call stack, looks like it's still focusing on a Drawer item?

[chrisglein]

Tested it locally - looks like there's still one phantom tab stop now on the home page:

Yep, I'm still seeing one. So it matches #408 (instead of having a ton). Of note, you can get some if you have some logbox warnings. I'm going to check a release build and see if that removes the last tab stop. If not... well it's still cutting down on the many drawer ones.

From the focusable warning call stack, looks like it's still focusing on a Drawer item?

Yep, that's preexisting (#407). I'm working on a change to refactor the drawer entirely and I'm hoping we can fix that error at the same time.

[chrisglein]

Release build still had one phantom tab stop (#408). So that seems to be a general issue with the react-navigation implementation that we'll need to address separately.