Rename method to set bubble bar expanded state [1/N]

Rename methods in BubbleBarViewController and BubbleBarView that set the
expanded state.
These will update the state using an animation.
Update the name to highlight this.
Enables us to create methods to set the state without animation.

Bug: 357115534
Test: refactor, presubmit
Flag: com.android.wm.shell.enable_bubble_bar
Change-Id: I9d2c46ab1640ab0b19f54103ab8cdb37a5d19dbb

quickstep/tests/multivalentScreenshotTests/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewScreenshotTest.kt

@@ -113,7 +113,7 @@ class BubbleBarViewScreenshotTest(emulationSpec: DeviceEmulationSpec) {
             val lp = FrameLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT)
             container.layoutParams = lp
             container.addView(bubbleBarView)
-            bubbleBarView.isExpanded = true
+            bubbleBarView.animateExpanded(true)
             container
         }
     }