The [Save] button cannot be clicked when the comment is disabled (via
`pointer-events: disabled;` in the CSS), and clicking the [Save] button
results in setting disabled to true. However, it is possible to click
save again before the style is applied. It's also possible to trigger
the button using a non-pointer-event (such as a key). With this change,
an extra check is added to the [Save] button's click handler to prevent
clicks when the component is disabled.
Bug: Issue 6972
Change-Id: I16117af31c5e7b5d7d49a025eebb690d8802b64b
fb3733ccb9