Support header and implementation jars in sdk

Add a new java_header_libs property that exports header jars (as
java_libs currently does) and switch java_libs to export implementation
jars instead.

Refactors implementation of the existing library sdk member type so
both properties can be supported from common code as they differ only
on the jar being exported.

Bug: 143678475
Test: m nothing
Change-Id: I04642122f72d083bbdfd3290624f957b71ee8875
diff --git a/sdk/sdk.go b/sdk/sdk.go
index 75c8585..c7e12b9 100644
--- a/sdk/sdk.go
+++ b/sdk/sdk.go
@@ -61,7 +61,12 @@
 }
 
 type sdkProperties struct {
-	// The list of java libraries in this SDK
+	// The list of java header libraries in this SDK
+	//
+	// This should be used for java libraries that are provided separately at runtime,
+	// e.g. through an APEX.
+	Java_header_libs []string
+	// The list of java implementation libraries in this SDK
 	Java_libs []string
 	// The list of native libraries in this SDK
 	Native_shared_libs []string
@@ -77,7 +82,7 @@
 }
 
 // Contains information about the sdk properties that list sdk members, e.g.
-// Java_libs.
+// Java_header_libs.
 type sdkMemberListProperty struct {
 	// the name of the property as used in a .bp file
 	name string
@@ -106,9 +111,14 @@
 	},
 	// Members from java package.
 	{
+		name:       "java_header_libs",
+		getter:     func(properties *sdkProperties) []string { return properties.Java_header_libs },
+		memberType: java.HeaderLibrarySdkMemberType,
+	},
+	{
 		name:       "java_libs",
 		getter:     func(properties *sdkProperties) []string { return properties.Java_libs },
-		memberType: java.LibrarySdkMemberType,
+		memberType: java.ImplLibrarySdkMemberType,
 	},
 	{
 		name:       "stubs_sources",