Cannot move edit text cursor to first position using character granularity.

Navigating over text backwards by character does not allow the cursor to get
at the beginning of the text and it stops one position before the start. Now
the cursor can get to index zero which is before the first character.

bug:7307336

Change-Id: I109b579835cc080907b20b01e0cf07811e962c6c

Author: sganov

core/java/android/view/View.java

@@ -7010,10 +7010,12 @@ private boolean previousAtGranularity(int granularity) {
         int current = getAccessibilityCursorPosition();
         if (current == ACCESSIBILITY_CURSOR_POSITION_UNDEFINED) {
             current = text.length();
+            setAccessibilityCursorPosition(current);
         } else if (granularity == AccessibilityNodeInfo.MOVEMENT_GRANULARITY_CHARACTER) {
             // When traversing by character we always put the cursor after the character
             // to ease edit and have to compensate before asking the for previous segment.
             current--;
+            setAccessibilityCursorPosition(current);
         }
         final int[] range = iterator.preceding(current);
         if (range == null) {