[grpc][Gpr_To_Absl_Logging] Migrating from gpr to absl logging - BUILD (#36588)

[grpc][Gpr_To_Absl_Logging] Migrating from gpr to absl logging - BUILD
In this CL we are just editing the build and bzl files to add dependencies.
This is done to prevent merge conflict and constantly having to re-make the make files using generate_projects.sh for each set of changes.

Closes #36588

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/36588 from tanvi-jagtap:build_src_cpp 1b7e617bdd
PiperOrigin-RevId: 633149794

src/cpp/ext/csm/BUILD

@@ -42,6 +42,7 @@ grpc_cc_library(
     external_deps = [
         "absl/functional:any_invocable",
         "absl/log:check",
+        "absl/log:log",
         "absl/status:statusor",
         "absl/strings",
         "absl/types:optional",

src/cpp/ext/gcp/BUILD

@@ -115,6 +115,7 @@ grpc_cc_library(
     ],
     external_deps = [
         "absl/base:core_headers",
+        "absl/log:log",
         "absl/numeric:int128",
         "absl/strings",
         "absl/strings:str_format",
@@ -157,6 +158,7 @@ grpc_cc_library(
         "absl/container:flat_hash_map",
         "absl/functional:any_invocable",
         "absl/log:check",
+        "absl/log:log",
         "absl/status",
         "absl/status:statusor",
         "absl/types:optional",