ios: dynamically load Dropbox API key

Load it at build time from a "dropbox.key" file. The file should contain the API
key in a single line.

ios/app/app.xcodeproj/project.pbxproj

 				0BB7DA181EC9E695007AAE98 /* Adjust ATS */,
 				DEC2069321CBBD6900072F03 /* Setup Fabric */,
 				DE11877A21EE09640078D059 /* Setup Google reverse URL handler */,
+				DE4F6D6E22005C0400DE699E /* Setup Dropbox */,
 			);
 			buildRules = (
 			);
 			shellPath = /bin/sh;
 			shellScript = "INFO_PLIST=\"$BUILT_PRODUCTS_DIR/$INFOPLIST_PATH\"\nREVERSED_CLIENT_ID=$(/usr/libexec/PlistBuddy -c \"Print :REVERSED_CLIENT_ID:\" $PROJECT_DIR/GoogleService-Info.plist)\n\n/usr/libexec/PlistBuddy -c \"Set :CFBundleURLTypes:1:CFBundleURLSchemes:0 $REVERSED_CLIENT_ID\" $INFO_PLIST\n";
 		};
+		DE4F6D6E22005C0400DE699E /* Setup Dropbox */ = {
+			isa = PBXShellScriptBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			inputFileListPaths = (
+			);
+			inputPaths = (
+			);
+			name = "Setup Dropbox";
+			outputFileListPaths = (
+			);
+			outputPaths = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+			shellPath = /bin/sh;
+			shellScript = "INFO_PLIST=\"$BUILT_PRODUCTS_DIR/$INFOPLIST_PATH\"\nDROPBOX_KEY_FILE=\"$PROJECT_DIR/dropbox.key\"\n\nif [[ -f $DROPBOX_KEY_FILE ]]; then\n    /usr/libexec/PlistBuddy -c \"Delete :LSApplicationQueriesSchemes\" $INFO_PLIST\n    /usr/libexec/PlistBuddy -c \"Add :LSApplicationQueriesSchemes array\" $INFO_PLIST\n    /usr/libexec/PlistBuddy -c \"Add :LSApplicationQueriesSchemes:0 string 'dbapi-2'\" $INFO_PLIST\n    /usr/libexec/PlistBuddy -c \"Add :LSApplicationQueriesSchemes:1 string 'dbapi-8-emm'\" $INFO_PLIST\n\n    DROPBOX_KEY=$(head -n 1 $DROPBOX_KEY_FILE)\n    /usr/libexec/PlistBuddy -c \"Add :CFBundleURLTypes:2:CFBundleURLName string dropbox\" $INFO_PLIST\n    /usr/libexec/PlistBuddy -c \"Add :CFBundleURLTypes:2:CFBundleURLSchemes array\" $INFO_PLIST\n    /usr/libexec/PlistBuddy -c \"Add :CFBundleURLTypes:2:CFBundleURLSchemes:0 string $DROPBOX_KEY\" $INFO_PLIST\nfi\n";
+		};
 		DEC2069321CBBD6900072F03 /* Setup Fabric */ = {
 			isa = PBXShellScriptBuildPhase;
 			buildActionMask = 2147483647;

ios/sdk/src/Info.plist

 	<string>1.9.0</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
-	<key>LSApplicationQueriesSchemes</key>
-	<array>
-		<string>dbapi-2</string>
-		<string>dbapi-8-emm</string>
-	</array>
 	<key>NSPrincipalClass</key>
 	<string></string>
 </dict>