Handle filename variations for prebuilt_etc in bp2build

Bp2build now handles these cases:

-filename is specified as a property
-if filename is not specified and filename_from_src = true,
	filename is set as the src
-filename defaults to the module name otherwise

Bug: 228353188
Test: bp2build/prebuilt_etc_conversion_test.go
Change-Id: Ia4c9b2c89f100e4ed9363dc3ba20ea501b776216

bp2build/prebuilt_etc_conversion_test.go

@@ -181,3 +181,87 @@ prebuilt_etc {
 				"dir":         `"etc"`,
 			})}})
 }
+
+func TestFilenameAsProperty(t *testing.T) {
+	runPrebuiltEtcTestCase(t, Bp2buildTestCase{
+		Description: "prebuilt_etc - filename is specified as a property ",
+		Filesystem:  map[string]string{},
+		Blueprint: `
+prebuilt_etc {
+    name: "foo",
+    src: "fooSrc",
+    filename: "fooFileName",
+}
+`,
+		ExpectedBazelTargets: []string{
+			MakeBazelTarget("prebuilt_file", "foo", AttrNameToString{
+				"filename": `"fooFileName"`,
+				"src":      `"fooSrc"`,
+				"dir":      `"etc"`,
+			})}})
+}
+
+func TestFileNameFromSrc(t *testing.T) {
+	runPrebuiltEtcTestCase(t, Bp2buildTestCase{
+		Description: "prebuilt_etc - filename_from_src is true  ",
+		Filesystem:  map[string]string{},
+		Blueprint: `
+prebuilt_etc {
+    name: "foo",
+    filename_from_src: true,
+    src: "fooSrc",
+}
+`,
+		ExpectedBazelTargets: []string{
+			MakeBazelTarget("prebuilt_file", "foo", AttrNameToString{
+				"filename": `"fooSrc"`,
+				"src":      `"fooSrc"`,
+				"dir":      `"etc"`,
+			})}})
+}
+
+func TestFileNameFromSrcMultipleSrcs(t *testing.T) {
+	runPrebuiltEtcTestCase(t, Bp2buildTestCase{
+		Description: "prebuilt_etc - filename_from_src is true but there are multiple srcs",
+		Filesystem:  map[string]string{},
+		Blueprint: `
+prebuilt_etc {
+    name: "foo",
+    filename_from_src: true,
+		arch: {
+        arm: {
+            src: "barSrc",
+        },
+        arm64: {
+            src: "bazSrc",
+        },
+	  }
+}
+`,
+		ExpectedBazelTargets: []string{
+			MakeBazelTarget("prebuilt_file", "foo", AttrNameToString{
+				"filename_from_src": `True`,
+				"dir":               `"etc"`,
+				"src": `select({
+        "//build/bazel/platforms/arch:arm": "barSrc",
+        "//build/bazel/platforms/arch:arm64": "bazSrc",
+        "//conditions:default": None,
+    })`,
+			})}})
+}
+
+func TestFilenameFromModuleName(t *testing.T) {
+	runPrebuiltEtcTestCase(t, Bp2buildTestCase{
+		Description: "prebuilt_etc - neither filename nor filename_from_src are specified ",
+		Filesystem:  map[string]string{},
+		Blueprint: `
+prebuilt_etc {
+    name: "foo",
+}
+`,
+		ExpectedBazelTargets: []string{
+			MakeBazelTarget("prebuilt_file", "foo", AttrNameToString{
+				"filename": `"foo"`,
+				"dir":      `"etc"`,
+			})}})
+}