Make default components public

[sebastianmarschall]

Is there a specific reason why almost all DefaultXXX composables are private?

Thats a huge pita if one wants to make even the smalles adaptions of any chat element. For example, I want the MessageComposer to not have an elevation of 4.dp. But thats hardcoded, I cant change it by parameters. I now have to copy the whole MessageComposer composable over but not only that I have to go through all default components that are used within MessageComposer and copy them over as well. Thats laborious, error prone and any changes that are made to those elements within the SDK I won't take notice off.