DO NOT MERGE Revert "okio: increase segment size to 8 KiB"

This reverts commit 147e5ea75d85f64f2b051a11ed1879dfa56050e9.

This CL caused MMS HTTP request failure probably due to a more
fundamental problem in system. Revert this so that at least the MMS
issue can be fixed.

b/24630124

Change-Id: I2af9223cf96c00fe28f817360c5e79572db3af10
diff --git a/okio/okio/src/main/java/okio/Segment.java b/okio/okio/src/main/java/okio/Segment.java
index 225ab13..61c8477 100644
--- a/okio/okio/src/main/java/okio/Segment.java
+++ b/okio/okio/src/main/java/okio/Segment.java
@@ -32,7 +32,7 @@
  */
 final class Segment {
   /** The size of all segments in bytes. */
-  static final int SIZE = 8192;
+  static final int SIZE = 2048;
 
   final byte[] data;