bp2build support for cc_prebuilt_library

while cc_prebuilt_library_(shared|static) were already supported,
the raw cc_prebuilt_library module type was not supported by
bp2build. This CL provides that functionality.

Also did a little bit of refactoring and cleaning.

Bug: 225938765
Test: Confirm output BUILD.bazel files look as expected. Confirm
      that build succeeds.
Change-Id: Ic004f88febc0e5b527f2ef420dbd96ecc55d2e09
diff --git a/bp2build/cc_prebuilt_library_static_test.go b/bp2build/cc_prebuilt_library_static_test.go
new file mode 100644
index 0000000..3feb1f1
--- /dev/null
+++ b/bp2build/cc_prebuilt_library_static_test.go
@@ -0,0 +1,98 @@
+// Copyright 2022 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package bp2build
+
+import (
+	"fmt"
+	"testing"
+
+	"android/soong/cc"
+)
+
+func TestStaticPrebuiltLibrary(t *testing.T) {
+	runBp2BuildTestCaseSimple(t,
+		bp2buildTestCase{
+			description:                "prebuilt library static simple",
+			moduleTypeUnderTest:        "cc_prebuilt_library_static",
+			moduleTypeUnderTestFactory: cc.PrebuiltStaticLibraryFactory,
+			filesystem: map[string]string{
+				"libf.so": "",
+			},
+			blueprint: `
+cc_prebuilt_library_static {
+	name: "libtest",
+	srcs: ["libf.so"],
+	bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{
+				makeBazelTarget("prebuilt_library_static", "libtest", attrNameToString{
+					"static_library": `"libf.so"`,
+				}),
+			},
+		})
+}
+
+func TestStaticPrebuiltLibraryWithArchVariance(t *testing.T) {
+	runBp2BuildTestCaseSimple(t,
+		bp2buildTestCase{
+			description:                "prebuilt library static with arch variance",
+			moduleTypeUnderTest:        "cc_prebuilt_library_static",
+			moduleTypeUnderTestFactory: cc.PrebuiltStaticLibraryFactory,
+			filesystem: map[string]string{
+				"libf.so": "",
+				"libg.so": "",
+			},
+			blueprint: `
+cc_prebuilt_library_static {
+	name: "libtest",
+	arch: {
+		arm64: { srcs: ["libf.so"], },
+		arm: { srcs: ["libg.so"], },
+	},
+	bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{
+				makeBazelTarget("prebuilt_library_static", "libtest", attrNameToString{
+					"static_library": `select({
+        "//build/bazel/platforms/arch:arm": "libg.so",
+        "//build/bazel/platforms/arch:arm64": "libf.so",
+        "//conditions:default": None,
+    })`,
+				}),
+			},
+		})
+}
+
+func TestStaticPrebuiltLibraryStaticStanzaFails(t *testing.T) {
+	runBp2BuildTestCaseSimple(t,
+		bp2buildTestCase{
+			description:                "prebuilt library with static stanza fails because multiple sources",
+			moduleTypeUnderTest:        "cc_prebuilt_library_static",
+			moduleTypeUnderTestFactory: cc.PrebuiltStaticLibraryFactory,
+			filesystem: map[string]string{
+				"libf.so": "",
+				"libg.so": "",
+			},
+			blueprint: `
+cc_prebuilt_library_static {
+	name: "libtest",
+	srcs: ["libf.so"],
+	static: {
+		srcs: ["libg.so"],
+	},
+	bazel_module: { bp2build_available: true },
+}`,
+			expectedErr: fmt.Errorf("Expected at most one source file"),
+		})
+}