Add missing includes checks.h/array_view.h

instead of relying on optional.h to included these 2 headers.

Bug: webrtc:9078
Change-Id: I7a4b3facd81690b8f107640487e129986c1f5ff6
Reviewed-on: https://webrtc-review.googlesource.com/68602
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22803}

api/audio_codecs/audio_format.h

@@ -17,6 +17,7 @@
 #include <utility>
 
 #include "api/optional.h"
+#include "rtc_base/checks.h"
 
 namespace webrtc {
 

api/rtptransceiverinterface.h

@@ -14,6 +14,7 @@
 #include <string>
 #include <vector>
 
+#include "api/array_view.h"
 #include "api/optional.h"
 #include "api/rtpreceiverinterface.h"
 #include "api/rtpsenderinterface.h"

logging/rtc_event_log/output/rtc_event_log_output_file_unittest.cc

@@ -8,11 +8,13 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include "logging/rtc_event_log/output/rtc_event_log_output_file.h"
+
 #include <fstream>
 #include <memory>
 #include <string>
 
-#include "logging/rtc_event_log/output/rtc_event_log_output_file.h"
+#include "rtc_base/checks.h"
 #include "rtc_base/ptr_util.h"
 #include "test/gtest.h"
 #include "test/testsupport/fileutils.h"

modules/audio_processing/aec3/matched_filter.h

@@ -15,6 +15,7 @@
 #include <memory>
 #include <vector>
 
+#include "api/array_view.h"
 #include "api/optional.h"
 #include "modules/audio_processing/aec3/aec3_common.h"
 #include "modules/audio_processing/aec3/downsampled_render_buffer.h"

rtc_base/string_to_number.cc

@@ -8,10 +8,12 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include "rtc_base/string_to_number.h"
+
 #include <cerrno>
 #include <cstdlib>
 
-#include "rtc_base/string_to_number.h"
+#include "rtc_base/checks.h"
 
 namespace rtc {
 namespace string_to_number_internal {

rtc_tools/network_tester/config_reader.cc

@@ -12,6 +12,8 @@
 #include <string>
 #include <vector>
 
+#include "rtc_base/checks.h"
+
 namespace webrtc {
 
 ConfigReader::ConfigReader(const std::string& config_file_path)