[Mono.Android] Use 'merge.SourceFile' to set 'ApiSince'.

Author: jpobst

external/Java.Interop

@@ -108,7 +108,6 @@
       <_Fixup>--fixup=metadata</_Fixup>
       <_Enums1>--preserve-enums --enumflags=enumflags --enumfields=map.csv --enummethods=methodmap.csv</_Enums1>
       <_Enums2>--enummetadata=$(IntermediateOutputPath)mcw\enummetadata</_Enums2>
-      <_Versions>@(_ApiVersion->'--apiversions="%(Identity)"', ' ')</_Versions>
       <_Annotations>--annotations="$(AndroidSdkDirectory)\platform-tools\api\annotations.zip"</_Annotations>
       <_Assembly>--assembly="Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null"</_Assembly>
       <_TypeMap>--type-map-report=$(IntermediateOutputPath)mcw\type-mapping.txt</_TypeMap>

src/Mono.Android/Mono.Android.targets

@@ -8,6 +8,26 @@
   <attr api-since="1" api-until="18" path="/api/package/interface" name="deprecated"
     >The assembly `Mono.Android.dll` for this API level will be removed in a future release.  Please update your `$(TargetFrameworkVersion)` to be v4.4 or greater.</attr>
 
+  <!-- Set ApiSince based on merge sourcefile -->
+  <attr api-since="10" path="/api/package//*[contains(@merge.SourceFile,'api-10.xml.in')]" name="api-since">10</attr>
+  <attr api-since="15" path="/api/package//*[contains(@merge.SourceFile,'api-15.xml.in')]" name="api-since">15</attr>
+  <attr api-since="16" path="/api/package//*[contains(@merge.SourceFile,'api-16.xml.in')]" name="api-since">16</attr>
+  <attr api-since="17" path="/api/package//*[contains(@merge.SourceFile,'api-17.xml.in')]" name="api-since">17</attr>
+  <attr api-since="18" path="/api/package//*[contains(@merge.SourceFile,'api-18.xml.in')]" name="api-since">18</attr>
+  <attr api-since="19" path="/api/package//*[contains(@merge.SourceFile,'api-19.xml.in')]" name="api-since">19</attr>
+  <attr api-since="20" path="/api/package//*[contains(@merge.SourceFile,'api-20.xml.in')]" name="api-since">20</attr>
+  <attr api-since="21" path="/api/package//*[contains(@merge.SourceFile,'api-21.xml.in')]" name="api-since">21</attr>
+  <attr api-since="22" path="/api/package//*[contains(@merge.SourceFile,'api-22.xml.in')]" name="api-since">22</attr>
+  <attr api-since="23" path="/api/package//*[contains(@merge.SourceFile,'api-23.xml.in')]" name="api-since">23</attr>
+  <attr api-since="24" path="/api/package//*[contains(@merge.SourceFile,'api-24.xml.in')]" name="api-since">24</attr>
+  <attr api-since="25" path="/api/package//*[contains(@merge.SourceFile,'api-25.xml.in')]" name="api-since">25</attr>
+  <attr api-since="26" path="/api/package//*[contains(@merge.SourceFile,'api-26.xml.in')]" name="api-since">26</attr>
+  <attr api-since="27" path="/api/package//*[contains(@merge.SourceFile,'api-27.xml.in')]" name="api-since">27</attr>
+  <attr api-since="28" path="/api/package//*[contains(@merge.SourceFile,'api-28.xml.in')]" name="api-since">28</attr>
+  <attr api-since="29" path="/api/package//*[contains(@merge.SourceFile,'api-29.xml.in')]" name="api-since">29</attr>
+  <attr api-since="30" path="/api/package//*[contains(@merge.SourceFile,'api-30.xml.in')]" name="api-since">30</attr>
+  <attr api-since="30" path="/api/package//*[contains(@merge.SourceFile,'api-R.xml.in')]" name="api-since">30</attr>
+
   <!-- FIXME: we should remove this fixup in the future release. It was
   introduced due to mismatching enum use, and we already marked the API as
   [Obsolete] -->