fix(material/tooltip): Tooltip should mark for check when visibility changes

This commit fixes an error in the tooltip component where it updates
a value used in a host binding without calling `markForCheck`. This does
not currently throw an error because `checkNoChanges` is broken for
`OnPush` components. However, the error was surfaced when testing an
"exhaustive" check that will check _all_ views, regardless of their
dirty state. The issue also doesn't really produce a _visible_ problem
because it occurs when the tooltip is hidden so the fact that the zoom
never updates doesn't make a real difference.

Author: atscott

src/material/tooltip/tooltip.ts

@@ -1105,6 +1105,9 @@ export class TooltipComponent implements OnDestroy {
     const hideClass = this._hideAnimation;
     tooltip.classList.remove(isVisible ? hideClass : showClass);
     tooltip.classList.add(isVisible ? showClass : hideClass);
+    if (this._isVisible !== isVisible) {
+      this._changeDetectorRef.markForCheck();
+    }
     this._isVisible = isVisible;
 
     // It's common for internal apps to disable animations using `* { animation: none !important }`