Improvements to download progress UI

Switch to LinearProgressIndicator where possible and show an indeterminate
progress bar while download progress is below 1%

Signed-off-by: Aayush Gupta <aayushgupta219@gmail.com>

app/src/main/res/drawable/progressbar_bg.xml

@@ -1,37 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?><!--
-  ~ Aurora Store
-  ~  Copyright (C) 2021, Rahul Kumar Patel <whyorean@gmail.com>
-  ~
-  ~  Aurora Store is free software: you can redistribute it and/or modify
-  ~  it under the terms of the GNU General Public License as published by
-  ~  the Free Software Foundation, either version 2 of the License, or
-  ~  (at your option) any later version.
-  ~
-  ~  Aurora Store is distributed in the hope that it will be useful,
-  ~  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  ~  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  ~  GNU General Public License for more details.
-  ~
-  ~  You should have received a copy of the GNU General Public License
-  ~  along with Aurora Store.  If not, see <http://www.gnu.org/licenses/>.
-  ~
-  -->
-
-<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
-
-    <item android:id="@android:id/background">
-        <shape>
-            <corners android:radius="8dp" />
-            <solid android:color="@color/colorScrim" />
-        </shape>
-    </item>
-
-    <item android:id="@android:id/progress">
-        <clip>
-            <shape>
-                <corners android:radius="8dp" />
-                <solid android:color="@color/colorScrimAlt" />
-            </shape>
-        </clip>
-    </item>
-</layer-list>