Add variant_prepend support for all the properties in bp2build

This is a follow up of aosp/2336916. All the properties that have
variant_prepend tag are supported in bp2build.

Bug: 261644490
Test: TH and modified tests with updated expected behaviors
Change-Id: I13bb5d4d8fcd38bf153fa9083c9c945aec2dfa19
diff --git a/bp2build/cc_library_headers_conversion_test.go b/bp2build/cc_library_headers_conversion_test.go
index 32500a0..072f5b3 100644
--- a/bp2build/cc_library_headers_conversion_test.go
+++ b/bp2build/cc_library_headers_conversion_test.go
@@ -186,6 +186,8 @@
 	})
 }
 
+// header_libs has "variant_prepend" tag. In bp2build output,
+// variant info(select) should go before general info.
 func TestCcLibraryHeadersOsSpecificHeader(t *testing.T) {
 	runCcLibraryHeadersTestCase(t, Bp2buildTestCase{
 		Description:                "cc_library_headers test with os-specific header_libs props",
@@ -247,14 +249,14 @@
 }`,
 		ExpectedBazelTargets: []string{
 			MakeBazelTarget("cc_library_headers", "foo_headers", AttrNameToString{
-				"deps": `[":base-lib"] + select({
+				"deps": `select({
         "//build/bazel/platforms/os:android": [":android-lib"],
         "//build/bazel/platforms/os:darwin": [":darwin-lib"],
         "//build/bazel/platforms/os:linux_bionic": [":linux_bionic-lib"],
         "//build/bazel/platforms/os:linux_glibc": [":linux-lib"],
         "//build/bazel/platforms/os:windows": [":windows-lib"],
         "//conditions:default": [],
-    })`,
+    }) + [":base-lib"]`,
 			}),
 		},
 	})