Get real timestamps, better frame durations.

Uses clock_gettime instead of using a spoofed "1" all the time.

Only offers approximate default FPS of 30 as the valid range,
instead of the true maximum reported by the device,
as actually changing it isn't hooked up yet.

Removes the sensor frame duration variable;
CTS at least will just default to reading from the timestamp.

BUG: b/29457051
TEST: unit tests pass. Some previously failing cts tests now pass.

Change-Id: I505d7dd51fe45de55214cb802184bea46245f316
diff --git a/modules/camera/3_4/Android.mk b/modules/camera/3_4/Android.mk
index 592aa2f..fbb9a4b 100644
--- a/modules/camera/3_4/Android.mk
+++ b/modules/camera/3_4/Android.mk
@@ -41,6 +41,7 @@
   camera.cpp \
   capture_request.cpp \
   format_metadata_factory.cpp \
+  metadata/boottime_state_delegate.cpp \
   metadata/enum_converter.cpp \
   metadata/metadata.cpp \
   metadata/metadata_reader.cpp \