Cast HIDL uint16_t to char16_t in AIDL cpp backend service

Note that 16 bit int in AIDL interface is char type, while the
corresponding type in cpp/ndk backend is chat16_t type.

See https://source.android.com/devices/architecture/aidl/aidl-backends#types

This CL changes all the casting from uint16_t to char16_t instead of
char to keep the right size of the data.

Test: make
Bug: 185627837
Change-Id: Ic41c7d15df62adb4f78216580fcd9af2c806d891
diff --git a/services/tuner/TunerFilter.cpp b/services/tuner/TunerFilter.cpp
index d3d138d..ca280f2 100644
--- a/services/tuner/TunerFilter.cpp
+++ b/services/tuner/TunerFilter.cpp
@@ -732,10 +732,10 @@
         DemuxFilterSectionEvent sectionEvent = e.section();
         TunerFilterSectionEvent tunerSection;
 
-        tunerSection.tableId = static_cast<char>(sectionEvent.tableId);
-        tunerSection.version = static_cast<char>(sectionEvent.version);
-        tunerSection.sectionNum = static_cast<char>(sectionEvent.sectionNum);
-        tunerSection.dataLength = static_cast<char>(sectionEvent.dataLength);
+        tunerSection.tableId = static_cast<char16_t>(sectionEvent.tableId);
+        tunerSection.version = static_cast<char16_t>(sectionEvent.version);
+        tunerSection.sectionNum = static_cast<char16_t>(sectionEvent.sectionNum);
+        tunerSection.dataLength = static_cast<char16_t>(sectionEvent.dataLength);
 
         TunerFilterEvent tunerEvent;
         tunerEvent.set<TunerFilterEvent::section>(move(tunerSection));
@@ -749,7 +749,7 @@
         DemuxFilterPesEvent pesEvent = e.pes();
         TunerFilterPesEvent tunerPes;
 
-        tunerPes.streamId = static_cast<char>(pesEvent.streamId);
+        tunerPes.streamId = static_cast<char16_t>(pesEvent.streamId);
         tunerPes.dataLength = static_cast<int>(pesEvent.dataLength);
         tunerPes.mpuSequenceNumber = static_cast<int>(pesEvent.mpuSequenceNumber);
 
@@ -777,9 +777,9 @@
         }
 
         if (tsRecordEvent.pid.getDiscriminator() == DemuxPid::hidl_discriminator::tPid) {
-            tunerTsRecord.pid = static_cast<char>(tsRecordEvent.pid.tPid());
+            tunerTsRecord.pid = static_cast<char16_t>(tsRecordEvent.pid.tPid());
         } else {
-            tunerTsRecord.pid = static_cast<char>(Constant::INVALID_TS_PID);
+            tunerTsRecord.pid = static_cast<char16_t>(Constant::INVALID_TS_PID);
         }
 
         tunerTsRecord.scIndexMask = scIndexMask;
@@ -839,7 +839,7 @@
         tunerDownload.itemFragmentIndex = static_cast<int>(downloadEvent.itemFragmentIndex);
         tunerDownload.mpuSequenceNumber = static_cast<int>(downloadEvent.mpuSequenceNumber);
         tunerDownload.lastItemFragmentIndex = static_cast<int>(downloadEvent.lastItemFragmentIndex);
-        tunerDownload.dataLength = static_cast<char>(downloadEvent.dataLength);
+        tunerDownload.dataLength = static_cast<char16_t>(downloadEvent.dataLength);
 
         TunerFilterEvent tunerEvent;
         tunerEvent.set<TunerFilterEvent::download>(move(tunerDownload));
@@ -853,7 +853,7 @@
         DemuxFilterIpPayloadEvent ipPayloadEvent = e.ipPayload();
         TunerFilterIpPayloadEvent tunerIpPayload;
 
-        tunerIpPayload.dataLength = static_cast<char>(ipPayloadEvent.dataLength);
+        tunerIpPayload.dataLength = static_cast<char16_t>(ipPayloadEvent.dataLength);
 
         TunerFilterEvent tunerEvent;
         tunerEvent.set<TunerFilterEvent::ipPayload>(move(tunerIpPayload));