Specify jnilib partition in Android-<target>.mk

Context
- Android-<target>.mk currently does not contain information about partition for its dependent unembedded jni libraries, but only lists the name of the unembedded jni libraries.
- If an android_app module depends on an unembedded jni library that is located in a different partition, make cannot find the library.

Implementation
- Create a string field partition in jniLib struct.
- Add variable "LOCAL_SOONG_JNI_LIBS_PARTITION_<target>", an array of mappings of the name of the jni library to its partition.

Bug: 154162945
Test: m
Change-Id: I6b8e1272ff59dc70e3dd6ce8c6c8e4686dad76df
diff --git a/cc/library.go b/cc/library.go
index 8804bbb..27c956c 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -2222,6 +2222,10 @@
 	mod.ModuleBase.MakeUninstallable()
 }
 
+func (library *libraryDecorator) getPartition() string {
+	return library.path.Partition()
+}
+
 func (library *libraryDecorator) getAPIListCoverageXMLPath() android.ModuleOutPath {
 	return library.apiListCoverageXmlPath
 }