Launcher3: Can't search out local app by Chinese

Description:
Chinese content type is Character.OTHER_LETTER.
When key matches,it check the content type. And
if type is Character.OTHER_LETTER, it doesn't
support search and break.

When the content type is Character.OTHER_LETTER,
make it work normally.

Bug: 63534074
Change-Id: I3713f24c9206fe16a8da2a23e6c90d68079dd533
(cherry picked from commit a9f4bffbfc)

src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithm.java

@@ -132,7 +132,8 @@ public class DefaultAppSearchAlgorithm implements SearchAlgorithm {
                 // Always a break point for a symbol
                 return true;
             default:
-                return false;
+                // Always a break point at first character
+                return  prevType == Character.UNASSIGNED;
         }
     }
 }

tests/src/com/android/launcher3/allapps/search/DefaultAppSearchAlgorithmTest.java

@@ -71,6 +71,10 @@ public class DefaultAppSearchAlgorithmTest extends InstrumentationTestCase {
         // match lower case words
         assertTrue(mAlgorithm.matches(getInfo("elephant"), "e"));
 
+        assertTrue(mAlgorithm.matches(getInfo("电子邮件"), "电"));
+        assertTrue(mAlgorithm.matches(getInfo("电子邮件"), "电子"));
+        assertFalse(mAlgorithm.matches(getInfo("电子邮件"), "子"));
+        assertFalse(mAlgorithm.matches(getInfo("电子邮件"), "邮件"));
     }
 
     private AppInfo getInfo(String title) {