Stop using Googletest legacy APIs.

Googletest recently started replacing the term Test Case by Test Suite.
From now on, the preferred API is TestSuite*; the older TestCase* API
will be slowly deprecated.

This CL moves WebRTC to the new set of APIs.

More info in [1].

This CL has been generated with this script:

declare -A items
items[TYPED_TEST_CASE]=TYPED_TEST_SUITE
items[TYPED_TEST_CASE_P]=TYPED_TEST_SUITE_P
items[REGISTER_TYPED_TEST_CASE_P]=REGISTER_TYPED_TEST_SUITE_P
items[INSTANTIATE_TYPED_TEST_CASE_P]=INSTANTIATE_TYPED_TEST_SUITE_P
items[INSTANTIATE_TEST_CASE_P]=INSTANTIATE_TEST_SUITE_P
for i in "${!items[@]}"
do
  git ls-files | xargs sed -i "s/\b$i\b/${items[$i]}/g"
done
git cl format

[1] - https://github.com/google/googletest/blob/master/googletest/docs/primer.md#beware-of-the-nomenclature

Bug: None
Change-Id: I5ae191e3046caf347aeee01554d5743548ab0e3f
Reviewed-on: https://webrtc-review.googlesource.com/c/118701
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26494}
diff --git a/rtc_base/string_to_number_unittest.cc b/rtc_base/string_to_number_unittest.cc
index fe5f88e..2c2dfcc 100644
--- a/rtc_base/string_to_number_unittest.cc
+++ b/rtc_base/string_to_number_unittest.cc
@@ -36,7 +36,7 @@
 template <typename T>
 class BasicNumberTest : public ::testing::Test {};
 
-TYPED_TEST_CASE_P(BasicNumberTest);
+TYPED_TEST_SUITE_P(BasicNumberTest);
 
 TYPED_TEST_P(BasicNumberTest, TestValidNumbers) {
   using T = TypeParam;
@@ -93,16 +93,16 @@
   EXPECT_EQ(absl::nullopt, StringToNumber<T>("5 "));
 }
 
-REGISTER_TYPED_TEST_CASE_P(BasicNumberTest,
-                           TestValidNumbers,
-                           TestInvalidNumbers,
-                           TestInvalidInputs);
+REGISTER_TYPED_TEST_SUITE_P(BasicNumberTest,
+                            TestValidNumbers,
+                            TestInvalidNumbers,
+                            TestInvalidInputs);
 
 }  // namespace
 
-INSTANTIATE_TYPED_TEST_CASE_P(StringToNumberTest_Integers,
-                              BasicNumberTest,
-                              IntegerTypes);
+INSTANTIATE_TYPED_TEST_SUITE_P(StringToNumberTest_Integers,
+                               BasicNumberTest,
+                               IntegerTypes);
 
 TEST(StringToNumberTest, TestSpecificValues) {
   EXPECT_EQ(absl::nullopt, StringToNumber<uint8_t>("256"));