Reduce max in-memory size of IMAP text from 16MB to 2MB

* Even 2MB is probably high, but it's far better than 16MB

Bug: 5573863
Change-Id: I00d6d84ebc538d41dbf5683bd078a6bcd802e584

src/com/android/email/mail/store/imap/ImapResponseParser.java

@@ -40,7 +40,7 @@ public class ImapResponseParser {
     /**
      * Literal larger than this will be stored in temp file.
      */
-    private static final int LITERAL_KEEP_IN_MEMORY_THRESHOLD = 16 * 1024 * 1024;
+    private static final int LITERAL_KEEP_IN_MEMORY_THRESHOLD = 2 * 1024 * 1024;
 
     /** Input stream */
     private final PeekableInputStream mIn;