Update droiddoc with combined generation of Java and Kotlin docs

Due to ownership change, this CL is a combination of the two CLs:

1) 1102398: Added droiddoc module to combined dokka, doclava and add
switcher.

Added ds-docs-switched that merges outputs of dokka, doclava, and
applies switcher4 to them.

Bug: 128540915
Test: m -j ds-docs-switched

===

2) 1098541: Combined target for dokka and doclava

Created a droiddoc module that creates reference docs using Kotlin.
Renamed droiddoc modules that only create one language ref-docs, and
created a genrule that merges them together.

Bug: 72394196
Bug: 138396395
Test: m -j ds-docs-kt
Test: m -j ds-docs-java
Test: m -j ds-docs

===

Change-Id: If9bed782feae84e986395a9ea6401025a51bc316

Android.bp

@@ -849,6 +849,11 @@ doc_defaults {
     create_stubs: false,
 }
 
+doc_defaults {
+    name: "framework-dokka-docs-default",
+    create_stubs: false,
+}
+
 stubs_defaults {
     name: "metalava-api-stubs-default",
     srcs: [
@@ -1020,7 +1025,7 @@ droiddoc {
 }
 
 droiddoc {
-    name: "ds-docs",
+    name: "ds-docs-java",
     defaults: ["framework-docs-default"],
     srcs: [
         ":framework-doc-stubs",
@@ -1048,6 +1053,58 @@ droiddoc {
         " -samplegroup Wearable -devsite -samplesdir development/samples/browseable ",
 }
 
+droiddoc {
+    name: "ds-docs-kt",
+    defaults: ["framework-dokka-docs-default"],
+    srcs: [
+        ":framework-doc-stubs",
+    ],
+    args: "-noJdkLink -links https://kotlinlang.org/api/latest/jvm/stdlib/^external/dokka/package-list " +
+    "-noStdlibLink",
+    proofread_file: "ds-dokka-proofread.txt",
+    dokka_enabled: true,
+}
+
+java_genrule {
+    name: "ds-docs",
+    tools: [
+        "zip2zip",
+        "merge_zips",
+    ],
+    srcs: [
+        ":ds-docs-java{.docs.zip}",
+        ":ds-docs-kt{.docs.zip}",
+    ],
+    out: ["ds-docs.zip"],
+    dist: {
+        targets: ["docs"],
+    },
+    cmd: "$(location zip2zip) -i $(location :ds-docs-kt{.docs.zip}) -o $(genDir)/ds-docs-kt-moved.zip **/*:en/reference/kotlin && " +
+         "$(location merge_zips) $(out) $(location :ds-docs-java{.docs.zip}) $(genDir)/ds-docs-kt-moved.zip",
+}
+
+java_genrule {
+    name: "ds-docs-switched",
+    tools: [
+        "switcher4",
+        "soong_zip",
+    ],
+    srcs: [
+        ":ds-docs-java{.docs.zip}",
+        ":ds-docs-kt{.docs.zip}",
+    ],
+    out: ["ds-docs-switched.zip"],
+    dist: {
+        targets: ["docs"],
+    },
+    cmd: "unzip $(location :ds-docs-java{.docs.zip}) -d $(genDir) && " +
+         "unzip $(location :ds-docs-kt{.docs.zip}) -d $(genDir)/en/reference/kotlin && " +
+         "SWITCHER=$$(cd $$(dirname $(location switcher4)) && pwd)/$$(basename $(location switcher4)) && " +
+         "(cd $(genDir)/en/reference && $$SWITCHER --work platform) && " +
+         "$(location soong_zip) -o $(out) -C $(genDir) -D $(genDir)",
+}
+
+
 droiddoc {
     name: "ds-static-docs",
     defaults: ["framework-docs-default"],