Cleanup BUILD.gn files from imports like foo:foo

Repalce all occurrences of foo:foo in deps with just foo in BUILD.gn
files.

Done with Sublime regex replace.
Find: \b([-a-zA-Z0-9_]+):+\1\b
In: *.gn
Replace with: \1

Bug: None
Change-Id: I40aba1b14face687a595b852ffe443cb20197611
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/127899
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27225}

examples/androidnativeapi/BUILD.gn

@@ -57,9 +57,9 @@ if (is_android) {
       "//media:rtc_internal_video_codecs",
       "//modules/audio_processing",
       "//modules/audio_processing:api",
-      "//modules/utility:utility",
+      "//modules/utility",
       "//pc:libjingle_peerconnection",
-      "//rtc_base:rtc_base",
+      "//rtc_base",
       "//rtc_base:rtc_base_approved",
       "//sdk/android:native_api_base",
       "//sdk/android:native_api_jni",