Define spaceship <=> operator for StrongAlias

This simplifies using standard functions that search for the
spaceship operator like std::tie.

Bug: None
Change-Id: Id7875b31858c3014b69a6eec0c5cf88ab58c7b1c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/478120
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Auto-Submit: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47880}

rtc_base/strong_alias.h

diff --git a/rtc_base/strong_alias.h b/rtc_base/strong_alias.h
index 8071a7e..c179ae9 100644
--- a/rtc_base/strong_alias.h
+++ b/rtc_base/strong_alias.h
@@ -50,20 +50,8 @@
   constexpr bool operator==(const StrongAlias& other) const {
     return value_ == other.value_;
   }
-  constexpr bool operator!=(const StrongAlias& other) const {
-    return value_ != other.value_;
-  }
-  constexpr bool operator<(const StrongAlias& other) const {
-    return value_ < other.value_;
-  }
-  constexpr bool operator<=(const StrongAlias& other) const {
-    return value_ <= other.value_;
-  }
-  constexpr bool operator>(const StrongAlias& other) const {
-    return value_ > other.value_;
-  }
-  constexpr bool operator>=(const StrongAlias& other) const {
-    return value_ >= other.value_;
+  constexpr auto operator<=>(const StrongAlias& other) const {
+    return value_ <=> other.value_;
   }
 
  protected: