Add support for writing byte arrays to parcels

b/13418320

Cherrypicked from f0190bff38b6c29abbfc4a877442f71fc3d7dad8
https://googleplex-android-review.git.corp.google.com/#/c/433320/

Change-Id: I2285df9e9d3dc8a6a54055b13b352b81660bf45d

include/binder/Parcel.h

diff --git a/include/binder/Parcel.h b/include/binder/Parcel.h
index 33b2f00..939cfbe 100644
--- a/include/binder/Parcel.h
+++ b/include/binder/Parcel.h
@@ -101,6 +101,7 @@
     status_t            writeStrongBinder(const sp<IBinder>& val);
     status_t            writeWeakBinder(const wp<IBinder>& val);
     status_t            write(const Flattenable& val);
+    status_t            writeByteArray(size_t len, const uint8_t *val);
 
     // Place a native_handle into the parcel (the native_handle's file-
     // descriptors are dup'ed, so it is safe to delete the native_handle

libs/binder/Parcel.cpp

diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index dea14bb..1162681 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -617,6 +617,17 @@
     return writeAligned(val);
 }
 
+status_t Parcel::writeByteArray(size_t len, const uint8_t *val) {
+    if (!val) {
+        return writeAligned(-1);
+    }
+    status_t ret = writeAligned(len);
+    if (ret == NO_ERROR) {
+        ret = write(val, len * sizeof(*val));
+    }
+    return ret;
+}
+
 status_t Parcel::writeInt64(int64_t val)
 {
     return writeAligned(val);