bp2build: support strip properties.

This CL adds support to bp2build for generating all strip-related
properties into a strip dictionary as a parameter in the cc_library
macro.

With the dictionary, it's easy to organize related attributes and
directly expand into a stripped_shared_library's attributes.

Test: //build/bazel/tests/bionic:compare_libc_stripping
Test: TH
Fixes: b/187928597
Change-Id: Ifea68d48fe295e71a43b12876cb168c475a62187
diff --git a/cc/strip.go b/cc/strip.go
index b1f34bb..c60e135 100644
--- a/cc/strip.go
+++ b/cc/strip.go
@@ -59,6 +59,7 @@
 	return !forceDisable && (forceEnable || defaultEnable)
 }
 
+// Keep this consistent with //build/bazel/rules/stripped_shared_library.bzl.
 func (stripper *Stripper) strip(actx android.ModuleContext, in android.Path, out android.ModuleOutPath,
 	flags StripFlags, isStaticLib bool) {
 	if actx.Darwin() {