Allow FbDialog to resize when the soft keyboard is shown

This change essentially sets the soft input mode of the FbDialog's window to SOFT_INPUT_ADJUST_RESIZE so that when the soft keyboard is shown, the dialog shrinks and the user can scroll the WebView to access the content that was previously inaccessible because it was occluded by the soft keyboard. In order to make this work, a few changes to how different views are sized were also required. The commit message describes it in detail.