Android: Build skia on top of libicu.so

It proves that skia does not depend on private APIs
in ICU because libicu.so is now available in NDK.

Also, it helps deprecate libandroidicu.so and allow
i18n module and UI rendering to be mainline.

Bug: b/174051744
Test: m droid

Cherry-pick of aosp/1508716. Modifies the Android.bp
generator instead of Android.bp directly.

Change-Id: Ibb608d80ce2b664d1273affb1992b1df923f7040
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/337723
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Reviewed-by: Julia Lavrova <jlavrova@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>

gn/gn_to_bp.py

@@ -229,7 +229,7 @@ cc_defaults {
         "skia_pgo_no_profile_use"
     ],
     shared_libs: [
-        "libandroidicu",
+        "libicu",
         "libharfbuzz_ng",
     ],
     static_libs: [