Revert "[fuchsia] Use SDK provided gn templates for v8_unittests"

This reverts commit 8d51d561.

Reason for revert: This has runtime failures because including
cmx fragments isn't working ocrrectly. Still investigating why
this wasn't discovered by CQ.

Original change's description:
> [fuchsia] Use SDK provided gn templates for v8_unittests
>
> cr_fuchsia_package is deprecated in favor of using the Fuchsia
> SDK provided rules directly.
>
> Bug: chromium:1092804
> Change-Id: I86a59b6a717cb0aa8c3473e8410bdd98f0ffd042
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3537883
> Reviewed-by: Victor Gomes <victorgomes@chromium.org>
> Reviewed-by: Wez <wez@chromium.org>
> Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> Commit-Queue: Bryant Chandler <bryantchandler@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#79763}

Bug: chromium:1092804
Change-Id: I33e8a6f07c99d7040cffa579a95508e79904889e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3572005
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79796}

test/unittests/BUILD.gn

@@ -7,24 +7,18 @@ import("../../gni/v8.gni")
 if (is_fuchsia) {
   import("//build/config/fuchsia/rules.gni")
 
-  fuchsia_component("v8_unittests_component") {
+  cr_fuchsia_package("v8_unittests_pkg") {
     testonly = true
-    manifest = "v8_unittests.cmx"
-    data_deps = [ ":unittests" ]
-    visibility = [ ":*" ]
-  }
-
-  fuchsia_package("v8_unittests_pkg") {
-    testonly = true
-    package_name = "v8_unittests"
-    deps = [ ":v8_unittests_component" ]
+    binary = ":unittests"
+    manifest = "../../gni/v8.cmx"
+    package_name_override = "v8_unittests"
   }
 
   fuchsia_package_runner("v8_unittests_fuchsia") {
     testonly = true
     use_cfv2 = false
     package = ":v8_unittests_pkg"
-    package_name = "v8_unittests"
+    package_name_override = "v8_unittests"
   }
 }
 

test/unittests/v8_unittests.cmx

-{
-  "include": [
-    "build/config/fuchsia/test/minimum_capabilities.test-cmx",
-    "gni/v8.cmx"
-  ],
-  "program": {
-    "binary": "unittests"
-  }
-}
\ No newline at end of file