Hidden `b-form-textarea` not auto-sizing when becoming visible

[tradingstratagem]

Describe the bug

When a textarea is initially hidden it isn't rendered correctly.
The rows property is not taken into account, so the textarea is very small.

Steps to reproduce the bug

1. Put a b-form-textarea inside a modal
2. Open the modal
3. The textarea has not the correct height
4. Type in something and it automatically adjust its height

Expected behavior

The textarea should have the correct height from the beginning

Before

After typing in a character

Versions

Libraries:

• BootstrapVue: 2.0.0-rc.28
• Bootstrap: 4.3.1
• Vue: 2.6.10

Environment:

• Device: Mac
• OS: macOS Mojave
• Browser: Chrome
• Version: 76

[tmorehouse]

PR #3937 should have this fixed (once it is merged into 2.0.0 stable branch)

[tradingstratagem]

Thank you

[tmorehouse]

BootstrapVue v2.0.0 stable has been released. See https://bootstrap-vue.js.org/docs/misc/changelog