Added System to get missing Android SDKs for AppVeyor

_build/GetAndroidDepencies.ps1

@@ -0,0 +1,39 @@
+$AndroidToolPath = "${env:ProgramFiles(x86)}\Android\android-sdk\tools\android.bat"
+
+if (!(Test-Path $AndroidToolPath)) {
+    $AndroidToolPath = "$env:localappdata\Android\android-sdk\tools\android.bat"
+}
+
+Function Get-AndroidSDKs() {
+    $output = & $AndroidToolPath list sdk --all
+    $sdks = $output |% {
+        if ($_ -match '(?<index>\d+)- (?<sdk>.+), revision (?<revision>[\d\.]+)') {
+            $sdk = New-Object PSObject
+            Add-Member -InputObject $sdk -MemberType NoteProperty -Name Index -Value $Matches.index
+            Add-Member -InputObject $sdk -MemberType NoteProperty -Name Name -Value $Matches.sdk
+            Add-Member -InputObject $sdk -MemberType NoteProperty -Name Revision -Value $Matches.revision
+            $sdk
+        }
+    }
+    $sdks
+}
+
+Function Install-AndroidSDK() {
+    [CmdletBinding()]
+    Param(
+        [Parameter(Mandatory=$true, Position=0)]
+        [PSObject[]]$sdks
+    )
+
+    $sdkIndexes = $sdks |% { $_.Index }
+    $sdkIndexArgument = [string]::Join(',',  $sdkIndexes)
+    Write-Output "Installing additional Android SDKs..."
+    $sdks | Format-Table Name
+
+    # Suppress the output to STDOUT
+    $null = Echo 'y' | & $AndroidToolPath update sdk -u -a -t $sdkIndexArgument
+}
+
+$sdk26 = Get-AndroidSDKs |? { $_.name -like 'sdk platform*API 26*' -or $_.name -like 'google apis*api 26' }
+
+Install-AndroidSDK -sdks $sdk26

appveyor.yml

@@ -16,6 +16,9 @@ skip_commits:
 init:
 - ps: git config --global core.autocrlf true
 
+before_build:
+- ps: .\_build\GetAndroidDepencies.ps1
+
 build_script:
 - ps: .\_build\build.ps1