[fuchsia] route fuchsia.sysmem2.Allocator

Fuchsia's fake-display will be migrating to sysmem2, which
requires fuchsia.sysmem2.Allocator to be routed anywhere that
fake-display is used (in tests).

In addition, this change routes fuchsia.sysmem2.Allocator
everywhere that fuchsia.sysmem.Allocator is routed (without
regard for whether needed by fake-display). This way flutter
engine can migrate to fuchsia.sysmem2.Allocator without needing
more protocol routing diffs.

flutter/flutter#146858

shell/platform/fuchsia/flutter/tests/integration/embedder/flutter-embedder-test.cc

@@ -237,7 +237,11 @@ void FlutterEmbedderTest::SetUpRealmBase() {
  Protocol{fuchsia::logger::LogSink::Name_},
  Protocol{fuchsia::inspect::InspectSink::Name_},
  Protocol{fuchsia::sysmem::Allocator::Name_},
- Protocol{fuchsia::sysmem2::Allocator::Name_},
+
+ // Replace string with
+ // fuchsia::sysmem2::Allocator::Name_
+ // when available (fuchsia SDK >= 19).
+ Protocol{"fuchsia.sysmem2.Allocator"},
  Protocol{fuchsia::tracing::provider::Registry::Name_},
  Protocol{kVulkanLoaderServiceName},
  },
@@ -250,7 +254,11 @@ void FlutterEmbedderTest::SetUpRealmBase() {
  .capabilities = {Protocol{fuchsia::logger::LogSink::Name_},
  Protocol{fuchsia::inspect::InspectSink::Name_},
  Protocol{fuchsia::sysmem::Allocator::Name_},
- Protocol{fuchsia::sysmem2::Allocator::Name_},
+
+ // Replace string with
+ // fuchsia::sysmem2::Allocator::Name_
+ // when available (fuchsia SDK >= 19).
+ Protocol{"fuchsia.sysmem2.Allocator"},
  Protocol{fuchsia::tracing::provider::Registry::Name_},
  Protocol{kVulkanLoaderServiceName}},
  .source = ParentRef{},

shell/platform/fuchsia/flutter/tests/integration/utils/portable_ui_test.cc

@@ -82,7 +82,11 @@ void PortableUITest::SetUpRealmBase() {
  .capabilities = {Protocol{fuchsia::logger::LogSink::Name_},
  Protocol{fuchsia::inspect::InspectSink::Name_},
  Protocol{fuchsia::sysmem::Allocator::Name_},
- Protocol{fuchsia::sysmem2::Allocator::Name_},
+
+ // Replace string with
+ // fuchsia::sysmem2::Allocator::Name_
+ // when available (fuchsia SDK >= 19).
+ Protocol{"fuchsia.sysmem2.Allocator"},
  Protocol{fuchsia::tracing::provider::Registry::Name_},
  Protocol{fuchsia::ui::input::ImeService::Name_},
  Protocol{kPosixSocketProviderName},