Remove objc tests from rtc_unittests and move tests to sdk_unittests

The tests in rtc_unittests_objc are old gtest based tests and
The tests in sdk_unittests are XCTest based tests.
The objc tests in rtc_unittest are causing problems [1],
so I think it's time to combine the two types of objc tests.

Renaming the files to match the existing sdk_unittests and
removing the use of gtest helper functions (eg, EXPECT_EQ)
are planned for follow-up CLs.

[1] https://webrtc-review.googlesource.com/c/src/+/261724/9

Bug: webrtc:8382
Change-Id: I9308b35f654c4479c9df72bf7cd7f4032e267eb2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/262380
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Daniel.L (Byoungchan) Lee <daniel.l@hpcnt.com>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36878}
diff --git a/sdk/objc/unittests/RTCPeerConnectionFactoryBuilderTest.mm b/sdk/objc/unittests/RTCPeerConnectionFactoryBuilderTest.mm
index 14131dc..1ec004b 100644
--- a/sdk/objc/unittests/RTCPeerConnectionFactoryBuilderTest.mm
+++ b/sdk/objc/unittests/RTCPeerConnectionFactoryBuilderTest.mm
@@ -9,6 +9,7 @@
  */
 
 #import <Foundation/Foundation.h>
+#import <XCTest/XCTest.h>
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -30,12 +31,10 @@
 #include "rtc_base/gunit.h"
 #include "rtc_base/system/unused.h"
 
-@interface RTCPeerConnectionFactoryBuilderTest : NSObject
-- (void)testBuilder;
-- (void)testDefaultComponentsBuilder;
+@interface RTCPeerConnectionFactoryBuilderTests : XCTestCase
 @end
 
-@implementation RTCPeerConnectionFactoryBuilderTest
+@implementation RTCPeerConnectionFactoryBuilderTests
 
 - (void)testBuilder {
   id factoryMock = OCMStrictClassMock([RTC_OBJC_TYPE(RTCPeerConnectionFactory) class]);
@@ -79,17 +78,3 @@
   OCMVerifyAll(factoryMock);
 }
 @end
-
-TEST(RTCPeerConnectionFactoryBuilderTest, BuilderTest) {
-  @autoreleasepool {
-    RTCPeerConnectionFactoryBuilderTest* test = [[RTCPeerConnectionFactoryBuilderTest alloc] init];
-    [test testBuilder];
-  }
-}
-
-TEST(RTCPeerConnectionFactoryBuilderTest, DefaultComponentsBuilderTest) {
-  @autoreleasepool {
-    RTCPeerConnectionFactoryBuilderTest* test = [[RTCPeerConnectionFactoryBuilderTest alloc] init];
-    [test testDefaultComponentsBuilder];
-  }
-}