Restructure targets file for AndroidSdk dir eval

$AndroidSdkPath and $AndroidSdkDirectory weren’t being evaluated early enough to be used in properties (so the value would be blank).  This works around that by evaluating conditions using the android sdk location later (eg: not putting the $AndroidSdkDirectory into a property which is then later used in a condition).  Also, the full path now gets updated in the Task if the .aar file does exist in the android sdk.

Author: Redth

template.targets

@@ -10,25 +10,15 @@
         <!-- Path to .aar file within the extracted contents of the cached download -->
         <_XbdAarFile_>m2repository\com\android\support\$AarKey$\$AarVersion$\$AarKey$-$AarVersion$.aar</_XbdAarFile_>
 
-        <!-- Path to .aar file within the Android SDK -->
-        <_XbdAarFileInSdk_>$(AndroidSdkPath)\extras\android\$(_XbdAarFile_)</_XbdAarFileInSdk_>
+        <!-- Full path to .aar file, assuming we had to download to the cache - we reset this later if it is in the sdk -->
+        <_XbdAarFileFullPath_>$(XamarinBuildDownloadDir)\$(_XbdKey_)\$(_XbdAarFile_)</_XbdAarFileFullPath_>
 
         <!-- Assembly name to embed .aar in -->
         <_XbdAssemblyName_>$XbdAssemblyName$</_XbdAssemblyName_>
     </PropertyGroup>
 
-    <!-- If the Android SDK does NOT have Support Libs installed -->
-    <PropertyGroup Condition="!Exists('$(_XbdAarFileInSdk_)')">
-        <_XbdAarFileFullPath_>$(XamarinBuildDownloadDir)$(_XbdKey_)\$(_XbdAarFile_)</_XbdAarFileFullPath_>
-    </PropertyGroup>
-
-    <!-- If the Android SDK DOES have Support Libs installed -->
-    <PropertyGroup Condition="Exists('$(_XbdAarFileInSdk_)')">
-        <_XbdAarFileFullPath_>$(_XbdAarFileInSdk_)</_XbdAarFileFullPath_>
-    </PropertyGroup>
-
     <ItemGroup>
-        <XamarinBuildDownload Include="$(_XbdKey_)" Condition="!Exists('$(_XbdAarFileInSdk_)')">
+        <XamarinBuildDownload Include="$(_XbdKey_)" Condition="!Exists('$(AndroidSdkDirectory)\extras\android\$(_XbdAarFile_)')">
             <Url>$(_XbdUrl_)</Url>
             <Kind>Zip</Kind>
             <Sha1>$(_XbdSha1_)</Sha1>
@@ -40,6 +30,11 @@
     </ItemGroup>
 
     <Target Name="_XbdRestoreItems_">
+        <!-- Check if the aar file is in the android sdk already and change the path to use to it, if it's found -->
+        <CreateProperty Value="$(AndroidSdkDirectory)\extras\android\$(_XbdAarFile_)" Condition="Exists('$(AndroidSdkDirectory)\extras\android\$(_XbdAarFile_)')">
+            <Output PropertyName="_XbdAarFileFullPath_" TaskParameter="Value" />
+        </CreateProperty>
+
         <ItemGroup>
             <XamarinBuildDownloadRestoreAssemblyAar Include="$(_XbdAarFileFullPath_)">
                 <LogicalName>__AndroidLibraryProjects__.zip</LogicalName>