Enable passing parameters to the MediaWriter at runtime (at start() call).

- estimate the moov box size for mp4 file writer based on the file
  size/duration limit and target bit rate.
- can switch to use 64 bit file offset at runtime

rebased

Change-Id: Ibbe1f57e91ab2605820d5d96e8048d11e5559c53
diff --git a/media/libstagefright/AMRWriter.cpp b/media/libstagefright/AMRWriter.cpp
index 8951f5b..6d1dd16 100644
--- a/media/libstagefright/AMRWriter.cpp
+++ b/media/libstagefright/AMRWriter.cpp
@@ -97,7 +97,7 @@
     return OK;
 }
 
-status_t AMRWriter::start() {
+status_t AMRWriter::start(MetaData *params) {
     if (mInitCheck != OK) {
         return mInitCheck;
     }