fix(bazel): allow compile_strategy to be (privately) imported (#25080)

compile_strategy() is used to decide whether to build Angular code
using ngc (legacy) or ngtsc (local). In order for g3 BUILD rules
to switch properly and allow testing of Ivy in g3, they need to
import this function.

This commit removes the _ prefix which allows the function to be
imported.

PR Close #25080

Author: alxhub

packages/bazel/src/ng_module.bzl

@@ -14,7 +14,7 @@ load(":rules_typescript.bzl",
     "ts_providers_dict_to_struct",
 )
 
-def _compile_strategy(ctx):
+def compile_strategy(ctx):
   """Detect which strategy should be used to implement ng_module.
 
   Depending on the value of the 'compile' define flag or the '_global_mode' attribute, ng_module
@@ -50,7 +50,7 @@ def _compiler_name(ctx):
     the name of the current compiler to be displayed in build output
   """
 
-  strategy = _compile_strategy(ctx)
+  strategy = compile_strategy(ctx)
   if strategy == 'legacy':
     return 'ngc'
   elif strategy == 'global':
@@ -72,7 +72,7 @@ def _enable_ivy_value(ctx):
     the value of enableIvy that needs to be set in angularCompilerOptions in the generated tsconfig
   """
 
-  strategy = _compile_strategy(ctx)
+  strategy = compile_strategy(ctx)
   if strategy == 'legacy':
     return False
   elif strategy == 'global':
@@ -95,7 +95,7 @@ def _include_ng_files(ctx):
     factory files), false otherwise
   """
 
-  strategy = _compile_strategy(ctx)
+  strategy = compile_strategy(ctx)
   return strategy == 'legacy' or strategy == 'global'
 
 def _basename_of(ctx, file):