bp2build: remove header globs in generated srcs.

Not needed anymore for bp2build-incremental since https://android-review.googlesource.com/q/topic:no-include-check.

Not needed for mixed builds either, since cc compile actions aren't sandboxed.

Fixes: 186488830
Test: treehugger and go tests

Change-Id: Ib5d4908dcce6bf910a653c457bb251d726e717d4

bp2build/cc_object_conversion_test.go

@@ -67,11 +67,7 @@ func TestCcObjectBp2Build(t *testing.T) {
         "-Iinclude",
         "-I.",
     ],
-    srcs = [
-        "a/b/c.c",
-        "a/b/bar.h",
-        "a/b/foo.h",
-    ],
+    srcs = ["a/b/c.c"],
 )`,
 			},
 		},