NEW_API: Expose searchSuggestThreshold searchable attribute

This lets the searchable activity specify the number of
characters needed to trigger suggestions. Before, this was
hard-coded at 0. This caused unnecessary querying of the
suggestion provider in cases where the provider does not
return suggestions for empty or short queries.

api/current.xml

@@ -6444,6 +6444,17 @@
  visibility="public"
 >
 </field>
+<field name="searchSuggestThreshold"
+ type="int"
+ transient="false"
+ volatile="false"
+ value="16843373"
+ static="true"
+ final="true"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</field>
 <field name="secondaryProgress"
  type="int"
  transient="false"

core/res/res/values/public.xml

@@ -1094,6 +1094,7 @@
    <public type="attr" name="tension" id="0x0101026a" />
    <public type="attr" name="extraTension" id="0x0101026b" />
    <public type="attr" name="density" id="0x0101026c" />
+   <public type="attr" name="searchSuggestThreshold" id="0x0101026d" />
 
    <public type="anim" name="anticipate_interpolator" id="0x010a0007" />
    <public type="anim" name="overshoot_interpolator" id="0x010a0008" />